multiplyv. t.[F. multiplier, L. multiplicare, fr. multiplex manifold. See Multitude, Complex.]1. To increase in number; to make more numerous; to add quantity to.()Impunity will multiply motives to disobedience. (Ames.)2. (Math.) To add (any given number or quantity) to itself a certain number of times; to find the product of by multiplication; thus 7 multiplied by 8 produces the number 56; to multiply two numbers. See the Note under Multiplication.()3. To increase (the amount of gold or silver) by the arts of alchemy.()Multiplying gear (Mach.), gear for increasing speed. -- Multiplying lens. (Opt.) See under Lens.()v. i.1. To become greater in number; to become numerous.()When men began to multiply on the face of the earth, and daughters were born unto them. (Gen. vi. 1.)2. To increase in extent and influence; to spread.()The word of God grew and multiplied. (Acts xii. 24.)3. To increase amount of gold or silver by the arts of alchemy.(Chaucer.)