[ pruh-pawr-shuh-nl, -pohr- ]
/ prəˈpɔr ʃə nl, -ˈpoʊr- /


having due proportion; corresponding.
being in or characterized by proportion.
of, relating to, or based on proportion; relative.
  1. (of two quantities) having the same or a constant ratio or relation: The quantities y and x are proportional if y/x = k, where k is the constant of proportionality.
  2. (of a first quantity with respect to a second quantity) a constant multiple of: The quantity y is proportional to x if y = kx, where k is the constant of proportionality.

Nearby words

  1. proponent,
  2. propontis,
  3. proport,
  4. proportion,
  5. proportionable,
  6. proportional counter,
  7. proportional font,
  8. proportional limit,
  9. proportional representation,
  10. proportional spacing

Origin of proportional

1350–1400; Middle English proporcional < Latin prōportiōnālis. See proportion, -al1

Related forms
Can be confusedproportional proportionate Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for proportional

British Dictionary definitions for proportional


/ (prəˈpɔːʃənəl) /


of, involving, or being in proportion
maths having or related by a constant ratio


maths an unknown term in a proportionin a/b = c/x, x is the fourth proportional
Derived Formsproportionality, nounproportionally, adverb

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for proportional



late 14c. (implied in proportionally), from Late Latin proportionalis "pertaining to proportions," from proportio (see proportion). Related: Proportionally.

Online Etymology Dictionary, © 2010 Douglas Harper