redoubtyoudaoicibaDictYouDict[redoubt 词源字典]
redoubt: [17] Redoubt ‘stronghold’ has no etymological connection with doubt (although redoubtable [14] does – it derives from the French ancestor of doubt, which originally meant ‘fear’, and so historically denotes ‘to be feared’). It was borrowed from French redoute, which goes back via obsolete Italian ridotta to medieval Latin reductus ‘hidden place, refuge’, a noun use of the past participle of Latin redūcere ‘bring back, withdraw’ (source of English reduce). The b was inserted under the influence of redoubtable.
=> reduce[redoubt etymology, redoubt origin, 英语词源]
redoundyoudaoicibaDictYouDict
redound: see redundant
reduceyoudaoicibaDictYouDict
reduce: [14] ‘Lessen, diminish’ is a comparatively recent semantic development for reduce. Its Latin ancestor was certainly not used in that sense. This was redūcere, a compound verb formed from the prefix re- ‘back, again’ and dūcere ‘lead, bring’ (source of English duct, duke, educate, etc). It meant literally ‘bring back’, hence ‘restore’ and also ‘withdraw’.

The original ‘bring back’ made the journey to English, and even survived into the early 17th century (‘reducing often to my memory the conceit of that Roman stoic’, Sir Henry Wotton, Elements of Architecture 1624). The sense ‘lessen, diminish’ seems to be the result of a semantic progression from ‘bring back to a particular condition’ via ‘bring back to order’ and ‘bring to subjection’.

=> duct, duke, educate, introduce, produce, redoubt
redundantyoudaoicibaDictYouDict
redundant: [17] Etymologically, something that is redundant ‘overflows’ because there is too much of it. The word comes from the present participle of Latin redundāre ‘flow back, overflow’ (source also of English redound [14]). This was a compound verb formed from the prefix re- ‘back, again’ and undāre ‘rise in waves, surge’, a derivative of unda ‘wave’ (source of English undulate).
=> redound, surround, undulate
reefyoudaoicibaDictYouDict
reef: English has two words reef, which both come from the same source, but have reached the language via different routes. That source was Old Norse rif ‘rib’, a close relative of English rib. Amongst its metaphorical senses were ‘horizontal section of sail’, which English acquired in the 14th century via Middle Dutch rif as riff, later reef, and ‘underwater ridge of rock’, which came into English in the 16th century via Middle Low German ref. The former was put to verbal use in the 17th century in the sense ‘furl sails’, which may underlie reefer ‘marijuana cigarette’ [20] – perhaps a ‘furled’ cigarette.
=> rib
reekyoudaoicibaDictYouDict
reek: [OE] Reek originally meant ‘smoke’ (Edinburgh was called Auld [old] Reekie because of its smoky chimneys, not because it smelled). The word came from a prehistoric Germanic *raukiz, which also produced German rauch, Dutch rook, Swedish rök, and Danish røk, all meaning ‘smoke’. It is likely that it was related to Latin ructāre ‘spew out’ (source of English eructate [17]), in which case the etymological notion underlying reek ‘smoke’ is of something ‘belching’ out. The English sense ‘bad smell’ emerged in the 17th century.
=> eructate
referyoudaoicibaDictYouDict
refer: [14] To refer something is etymologically to ‘carry it back’. The word comes via Old French referer from Latin referre, a compound verb formed from the prefix re- ‘back’ and ferre ‘carry’ (source of English fertile and related to English bear). Of its derivatives, referee [16] is an English coinage, and referendum [19] is an adoption of the neuter gerundive of referre – literally, ‘that which is to be referred’. Relātus, which was used as the past participle of Latin referre, has given English relate.
=> bear, referee, referendum
refineyoudaoicibaDictYouDict
refine: see fine
reflectyoudaoicibaDictYouDict
reflect: [15] To reflect something is etymologically to ‘bend it back’. The word comes via Old French reflecter from Latin reflectere ‘bend back’, a compound verb formed from the prefix re- ‘back’ and flectere ‘bend’ (source also of English deflect [17], flex [16], flexible [15], inflect [15], etc). The word’s optical application is a post-Latin development.
=> deflect, flex, flexible, inflect
refrainyoudaoicibaDictYouDict
refrain: Refrain ‘chorus of a song’ [14] and refrain ‘desist’ [14] are different words. The former comes via Old French refrain from Provençal refranh. This was a derivative of the verb refranhar, which went back via Vulgar Latin *refrangere to Latin refringere ‘break off’ (source of English refract [17]). The etymological notion underlying the word is that the chorus of a song ‘breaks off’ and then resumes. Refrain ‘desist’ is descended from Latin refrēnāre ‘hold back’, a compound verb formed from the prefix re- ‘back’ and frēnum ‘bridle’. It reached English via Old French refrener.
=> fraction, refract
refugeyoudaoicibaDictYouDict
refuge: [14] A refuge is etymologically a place one ‘flees’ to in order to get away from danger. The word comes via Old French refuge from Latin refugium, a derivative of refugere. This was a compound verb formed from the prefix re- ‘away’ and fugere ‘flee’ (source of English fugitive [14] and fugue [16]). The derivative refugee [17] is an adaptation of refugié, the past participle of modern French refugier ‘take refuge’.
=> fugitive, refugee
refulgentyoudaoicibaDictYouDict
refulgent: see flame
refuseyoudaoicibaDictYouDict
refuse: [14] Refuse comes via Old French refuser from an unrecorded Vulgar Latin *refūsāre. It is not altogether clear where this came from, for it has no direct Latin antecedent. One theory is that it represents a blend of Latin recūsāre ‘refuse’ (source of English recusant [16]), a compound verb based on causa ‘cause’, and refūtāre ‘rebut’ (source of English refute [16]), a compound verb based on the element *fūt-, found also in English confute [16].

But another long-established school of thought derives it from refūsus, the past participle of Latin refundere ‘pour back’ (source of English refund [14]) – the underlying notion being of something ‘poured back’ or ‘rejected’. The noun refuse ‘rubbish’ [15] probably comes from Old French refus ‘refusal’, a derivative of refuser ‘refuse’.

refuteyoudaoicibaDictYouDict
refute: see beat
regalyoudaoicibaDictYouDict
regal: [14] Regal and royal are doublets: that is to say, they come from the same ultimate source, but have diverged over the centuries. This source was rēgālis, a derivative of Latin rēx ‘king’. This came from Indo-European *rēg-, which also produced the Sanskrit ancestor of English rajah, and was a lengthened version of *reg-, source of English rector, regiment, region, regular, reign, right, rule, etc. Regal was probably borrowed direct from Latin, whereas royal was routed via Old French. Also from rēx come regalia [16] and regicide [16].
=> rajah, rector, regiment, region, regular, reign, right, royal, rule
regaleyoudaoicibaDictYouDict
regale: see gallant
regardyoudaoicibaDictYouDict
regard: [14] The notions of ‘looking at something, keeping it in sight’ and ‘guarding it’ are closely linked, and often coexist in single words. Watch is an example, and so was Old French garder, ancestor of English guard. Addition of the prefix re- ‘back’ produced regarder ‘look back at, keep one’s eyes on’, hence simply ‘look at’. The Anglo-Norman version of the word gave English reward.
=> guard, reward, ward
regattayoudaoicibaDictYouDict
regatta: [17] The word regatta originated in Italy, and at first denoted a gondola race on the Grand Canal in Venice. It appears to have been derived from a Venetian dialect verb rigattare ‘contend, fight’, of uncertain origin. The first record of its application to a boat race in England is in June 1775, when a ‘regatta’ was held on the Thames: the Public advertiser noted that ‘The Regatta will keep at home many of our Nobility and wealthy Commoners’, and Dr Johnson wrote to his friend Mrs Thrale on June 21 ‘I am glad you are to be at the regatta’.
regentyoudaoicibaDictYouDict
regent: [14] Regent is one of a large family of English words that go back to Latin regere ‘rule’, a descendant of the Indo-European base reg- ‘move in a straight line’, hence ‘direct, guide, rule’. Others include correct, direct, dirge, erect, rector, régime [18], regimen [14] (and its more heavily disguised twin realm), regiment [14] (which originally meant ‘government’), region [14] (etymologically a ‘governed area’), resurrect, source, and surge. Regent itself comes from the present participle of the Latin verb.

Related words in Latin include rēx ‘king’ (source of English regal, regalia, royal, etc), rēgula ‘rule’ (source of English rail ‘bar’, regular, rule, etc), and rēgnum ‘kingship’ (source of English reign); and among other English words from the same Indo-European source are raj, rich, and right.

=> address, correct, direct, dirge, dress, erect, rajah, realm, rector, regiment, region, regular, reign, right, royal, rule
registeryoudaoicibaDictYouDict
register: [14] Register comes via Old French registre from late Latin regestum ‘list’. This was a noun use of the past participle of regerere ‘bring back’, hence ‘set down, record’, a compound verb formed from the prefix re- ‘back, again’ and gerere ‘bring, carry’ (source also of English congest, digest, gesture, jester, suggest, etc).
=> congest, digest, gesture, jester, suggest