multiply (v.)

mid-12c., multeplien, "to cause to become many, cause to increase in number or quantity," from Old French multiplier, mouteplier (12c.) "increase, get bigger; flourish; breed; extend, enrich," from Latin multiplicare "to increase," from multiplex (genitive multiplicis) "having many folds, many times as great in number," from combining form of multus"much, many" (see multi-) + -plex "-fold," from PIE root *plek- "to plait."

Intransitive sense of "grow or increase in number or extent" (especially "to have children, produce offspring") is from mid-14c. Mathematical sense "perform the process of multiplication" is attested from late 14c. Related: Multiplied; multiplying.

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Definitions of multiply
multiply (v.)
combine by multiplication;
multiply 10 by 15
multiply (v.)
combine or increase by multiplication;
He managed to multiply his profits
Synonyms: manifold
multiply (v.)
have young (animals) or reproduce (organisms);
Synonyms: breed
multiply (v.)
have offspring or produce more individuals of a given animal or plant;
Synonyms: reproduce / procreate
multiply (adv.)
in several ways; in a multiple manner;
they were multiply checked for errors