-kshən noun
( -s )
Etymology: Middle English subtraccion, from Late Latin subtraction-, subtractio, from Latin subtractus (past participle of subtrahere ) + -ion-, -io -ion
: an act, operation, or instance of subtracting: as
a. : the withdrawing or withholding from one a right (as customary services, fealty, rents, suit and service, conjugal rights, and tithes) to which he is entitled
b. : a process of logical abstraction whereby one class is excepted from another in which it is naturally included or a connotation is withdrawn from another connotation which includes it
c. : a mathematical process in which one number or quantity is deducted from another and which can be generalized by the formula m-s.r in which the remainder r when added to the subtrahend s always reproduces the minuend m : the inverse of addition
• sub·trac·tion·al -kshən ə l, -kshnəl adjective