multiply

From Old French multiplier, from Latin multiplicō, from multi (“many”) + plicō (“to fold”).

The noun presumably derives from the verb.

• enPR: mŭlʹtĭ-plī, IPA^(key): /ˈmʌltɪplaɪ/

• Audio (Southern England):

  (file)

multiply (third-person singular simple present multiplies, present participle multiplying, simple past and past participle multiplied)

1. (transitive) To increase the amount, degree or number of (something).
   • 1786, Fisher Ames, Lucius Junius Brutus:

     The motives to refuse obedience to government are many and strong ; impunity will multiply and enforce them

   • 1843, Transactions of the Royal Entomological Society of London:

     It would indeed be easy to multiply modern authorities respecting locustal food; one more authority shall suffice, from which it will appear that the Arabs make a sort of locust bread.

2. (transitive, arithmetic, with by) To perform multiplication on (a number).

   when you multiply 3 by 7, you get 21;  he multiplied several numbers

   • 2025 April 3, Felix Salmon, “How to read the White House's tariff formula”, in Axios‎^[1], archived from the original on 5 April 2025:

     But that can be ignored, because the USTR has set ε at 4 and φ at 0.25, so when computed give an overall multiplier of 1 for the imports number. And multiplying by 1 makes no difference at all.

3. (intransitive) To grow in number.
4. (intransitive) To breed or propagate.
   • 2013 July 20, “Welcome to the plastisphere”, in The Economist‎^[2], volume 408, number 8845, archived from the original on 8 March 2023:

     [The researchers] noticed many of their pieces of [plastic marine] debris sported surface pits around two microns across. […] Closer examination showed that some of these pits did, indeed, contain bacteria, and that in several cases these bacteria were dividing and thus, by the perverse arithmetic of biological terminology, multiplying.

5. (intransitive, arithmetic) To perform multiplication.

   He had been multiplying, but it occurred to him he needed to resolve the exponents, first.

   • 2022 August 7, Alec Wilkinson, “Could learning algebra in my 60s make me smarter?”, in The Guardian‎^[3], archived from the original on 22 March 2023:

     I could add and subtract and multiply and divide, but I entered the wilderness when words became equations.

6. (transitive, rare) To be a factor in a multiplication with (another factor).
   • 1983, Graham Flegg, Numbers‎^[4], Dover, published 2002, →ISBN, page 154:

     This follows a similar process, counters having to be removed and replaced at each stage of the remaining part of the calculation except the final one, where 2 multiplies 3 to give 6.

   • 1993, Edward T. Dowling, Schaum's Outline of Theory and Problems of Mathematical Methods for Business and Economics‎^[5], →ISBN, page 14:

     Of all the possible combinations of factors above, only ${\displaystyle (2\cdot 4)+(3\cdot 5)=23}$. Carefully arranging the factors, therefore, to ensure that 2 multiplies 4 and 3 multiplies 5, we have
     ${\displaystyle 6x^{2}+23x+20=(2x+5)(3x+4)}$

• Synonym: manifold

multiply (plural multiplies)

1. (computer science) An act or instance of multiplying.
   • 1975, Byte, numbers 1-8, page 14:

     The extended instruction set may double the speed again if a lot of multiplies and divides are done.

   • 2004, C. K. Birdsall, A. B. Langdon, Plasma Physics via Computer Simulation, page 75:

     List the number of adds and multiplies for each of the forms (6) , (7), and (8).

From multiple + -ly.

• enPR: mŭlʹtĭ-plē, IPA^(key): /ˈmʌltɪpli/

• Audio (Southern England):

  (file)

multiply (not comparable)

1. In many or multiple ways.

multi- +‎ ply

multiply (not comparable)

1. Having more than one ply or layer; multilayered.
   • 1956, Official Gazette of the United States Patent Office, page 732:

     2,751,151. MULTIPLY PAPER SACKS. […] A multiply paper bag […] the plies of the side flaps being stepped longitudinally of the bag […]