- subtract
[subtract 词源字典] - subtract: [16] To subtract something is etymologically to ‘pull it away’. The word comes from subtractus, the past participle of Latin subtrahere ‘pull away’. This was a compound verb formed from the prefix sub-, usually ‘under’ but here used in the sense ‘away’, and trahere ‘pull’ (source of English traction, tractor, trait, etc). The strictly mathematical use of the word is a post-Latin development.
=> contract, retract, traction, tractor, trait[subtract etymology, subtract origin, 英语词源] - subtract (v.)
- 1530s, "withdraw, withhold, take away, deduct," a back-formation from subtraction (q.v.), or else from Latin subtractus, past participle of subtrahere "take away, draw off." Related: Subtracted; subtracting. Mathematical calculation sense is from 1550s. Earlier verb form was subtraien (early 15c. in the mathematical sense), which is directly from the Latin verb.
Here he teches þe Craft how þou schalt know, whan þou hast subtrayd, wheþer þou hast wel ydo or no. ["Craft of Numbering," c. 1425]
