/səbˈtrækt/
[verb] To take away a number or amount from another number, making it smaller. More generally, it means to remove something from a larger whole.
Before calculators, 'subtract' literally meant to drag something out from underneath — like pulling a rug from under a number.
The word 'subtract' comes from Latin, built from two clear parts: the prefix 'sub-', meaning 'under' or 'from below', and the verb 'trahere', meaning 'to pull' or 'to drag'. Put together, the Latin verb 'subtrahere' carried the vivid physical image of pulling something out from beneath, dragging it away from a larger whole. It was the same sensation as yanking a stone from the bottom of a pile — the pile above collapses slightly, becomes less. This root 'trahere' was extraordinarily productive in Latin and gave English a whole family of words: Latin trahere → Old French traire → English 'trace'; Latin abstrahere → English 'abstract'; Latin contrahere → Old French contracter → English 'contract'; and Latin distrahere → Old French distraire → English 'distract'. Every time you feel distracted, something is etymologically dragging you away.
The past participle of 'subtrahere' in Latin was 'subtractus', and it is from this form that English borrowed the word. By the time Latin evolved into Medieval Latin — the scholarly and scientific language of the Middle Ages — 'subtrahere' and 'subtractus' were being used in mathematical contexts, meaning to take one quantity away from another. Medieval scholars and mathematicians writing in Latin kept this precise arithmetical sense alive for centuries before English ever encountered it.
The word entered English in the 16th century, around the 1530s and 1540s, arriving during a remarkable period when scholars and scientists were borrowing heavily from Latin to build a new vocabulary for mathematics, science, and philosophy. Before 'subtract' arrived, English speakers used a more homely word for the same operation: 'withdraw'. You would 'withdraw' three from ten to get seven. The Latinate newcomer 'subtract' gradually replaced it in mathematical writing, sounding more precise and authoritative — the language of the schoolroom and the counting house.
Interestingly, the noun form 'subtraction' actually appeared in English slightly before the verb. 'Subtraction' was recorded in English mathematical texts as early as the late 14th and early 15th centuries — borrowed directly from the Medieval Latin noun 'subtractio'. Writers were describing the concept of subtraction before the verb 'to subtract' had fully taken hold in the language. This pattern — where a noun arrives first and the verb follows — is not unusual in English, and it reflects how new ideas often enter a language through specialist texts and technical writing before they spread into everyday speech.
Today, 'subtract' lives almost entirely in mathematical and educational contexts, but its older, broader sense — simply removing something from something else — survives in careful writing. You might read that a disappointment 'subtracted from the joy of the occasion', and in that phrase the original Latin image briefly reappears: something is being dragged away from underneath, leaving the whole a little smaller, a little less complete than it was before.