afflict (v.)youdaoicibaDictYouDict[afflict 词源字典]
late 14c., "to cast down," from Old French aflicter, from Latin afflictare "to damage, harass, torment," frequentative of affligere (past participle afflictus) "to dash down, overthrow," from ad- "to" (see ad-) + fligere (past participle flictus) "to strike," from PIE root *bhlig- "to strike" (cognates: Greek phlibein "to press, crush," Czech blizna "scar," Welsh blif "catapult"). Transferred meaning of "trouble, distress," is first recorded 1530s. Related: Afflicted; afflicting.[afflict etymology, afflict origin, 英语词源]
nightmare (n.)youdaoicibaDictYouDict
late 13c., "an evil female spirit afflicting sleepers with a feeling of suffocation," compounded from night + mare (3) "goblin that causes nightmares, incubus." Meaning shifted mid-16c. from the incubus to the suffocating sensation it causes. Sense of "any bad dream" first recorded 1829; that of "very distressing experience" is from 1831. Cognate with Middle Dutch nachtmare, German Nachtmahr.
calentureyoudaoicibaDictYouDict
"Feverish delirium formerly thought of as afflicting sailors in the tropics", Late 16th century: from French, from Spanish calentura 'fever', from calentar 'be hot', based on Latin calere 'be warm'.