multiply

UK: /ˈmʌltɪplaɪ/

US: /ˈmʌltəˌplaɪ/

US: (v. mul′tə plī′; adv. mul′tə plē)

WordReference Random House Learner's Dictionary of American English © 2026

mul•ti•ply¹ /ˈmʌltəˌplaɪ/   v., -plied, -ply•ing. 

1. to find the product (of numbers) by multiplication: [~ + object + and + object]
   Multiply the length and width.
   [~ + object + by + object]
   Multiply the length by the width to get the area.
   [no object]
   You made a mistake when you multiplied; you should have divided.
2. to increase in number by giving birth to offspring:
   [no object] Soon the insects multiplied and destroyed all the crops.
3. to (cause to) grow in number, etc.;
   increase: [no object]
   Our problems have multiplied under your leadership.
   [~ + object]
   The problems are multiplied when we consider the cost overruns.

See -plic-.

Collins Concise English Dictionary © HarperCollins Publishers::

multiply / ˈmʌltɪˌplaɪ/ verb ( -plies, -plying, -plied)

1. to increase or cause to increase in number, quantity, or degree
2. (transitive) to combine (two numbers or quantities) by multiplication
3. (intransitive) to increase in number by reproduction

Etymology: 13th Century: from Old French multiplier, from Latin multiplicāre to multiply, from multus much, many + plicāre to fold

ˈmultiˌpliable, ˈmultiˌplicable adjective

WordReference Random House Unabridged Dictionary of American English © 2026

mul•ti-ply  (mul′tē plī′, mul′tī-), adj. 

1. having or composed of several plies:
   a multi-ply fabric.

• 1935–40

mul•ti•ply¹  (mul′tə plī′), v., -plied, -ply•ing. 
v.t. 

1. to make many or manifold;
   increase the number, quantity, etc., of.
2. [Arith.] to find the product of by multiplication.
3. Animal Husbandry to breed (animals).
4. to propagate (plants).
5. to increase by procreation.

v.i. 

6. to grow in number, quantity, etc.;
   increase.
7. [Arith.] to perform the process of multiplication.
8. to increase in number by procreation or natural generation.

• Latin multiplicāre. See multi-, ply²
• Old French multiplier
• Middle English multiplien 1225–75

Synonyms

• 6. magnify, enlarge, intensify.

mul•ti•ply²  (mul′tə plē), adv. 

1. in several or many ways;
   in a multiple manner;
   manifoldly.

• multiple + -ly 1880–85