contractyoudaoicibaDictYouDict[contract 词源字典]
contract: [14] English acquired the word contract in stages, although in all cases the ultimate source was contractus, the past participle of Latin contrahere, a compound verb formed from the prefix com- ‘together’ and trahere ‘pull, draw’ (source of English traction and tractor). This meant literally ‘pull together’, but it had a variety of metaphorical senses, including ‘bring about’ and ‘enter into an agreement’, and it was the latter which first passed into English via Old French as a noun meaning ‘mutual agreement’.

The arrival of the verb contract did not happen until the 16th century; it developed from an earlier adjective contract, which came again from Old French contract. This introduced a further sense of Latin contrahere; ‘become narrowed, get smaller’.
=> distract, retract, traction, tractor[contract etymology, contract origin, 英语词源]
rally (v.1)youdaoicibaDictYouDict
"bring together," c. 1600, from French rallier, from Old French ralier "reassemble, unite again," from re- "again" (see re-) + alier "unite" (see ally (v.)). Intransitive meaning "pull together hastily, recover order, revive, rouse" is from 1660s. Related: Rallied; rallying. Rally round the flag (1862) is a line from popular American Civil War song "Battle Cry of Freedom."