The word deduct is very Latin-sounding. Which is no surprise, because it is Latin:
early 15c., from Latin deductus, past participle of deducere “lead down, bring away;” see deduce, with which it formerly was interchangeable. Technically, deduct refers to taking away portions or amounts; subtract to taking away numbers. Related: Deducted; deducting.
The natural Saxon word would be “take away”. But it is interesting to see that “technically” deduct means to take away amounts, whereas subtract means to take away numbers. I’m not wholly sure if anyone follows this usage, to be honest. But if they do, us Anglishers have two options.
- Just replace both deduct and subtract with “take away”.
- Try to find another word so we can replace both words.
In option two, English has the handy little word “dock”. You can dock a tail, and you can dock wages. Both cases, we are taking about “portions or amounts”.
Therefore, it seems clear: in non-technical usage, both subtract and deduct can be replaced with either take away or dock, but in technical contexts, subtract becomes take away and deduct becomes dock.
© 2017-2018 Bryan A. J. Parry
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