[pruh-pawr-shuh-nl, -pohr-]


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.

Origin of proportional

1350–1400; Middle English proporcional < Latin prōportiōnālis. See proportion, -al1
Related formspro·por·tion·al·i·ty, nounpro·por·tion·al·ly, adverbin·ter·pro·por·tion·al, adjectivenon·pro·por·tion·al, adjectivenon·pro·por·tion·al·ly, adverbsub·pro·por·tion·al, adjectivesub·pro·por·tion·al·ly, adverbun·pro·por·tion·al, adjectiveun·pro·por·tion·al·ly, adverb
Can be confusedproportional proportionate

Synonyms for proportional Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

British Dictionary definitions for non-proportional



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 non-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