noun

1. the comparative relation between parts, things, or elements with respect to size, amount, degree, etc.; ratio
2. a part, share, or portion, esp. in its relation to the whole; quota
3. relationship between parts or things; esp., harmonious, proper, or desirable relationship; balance or symmetry
4. size, degree, or extent relative to a standard
5. dimensions a building of large proportions
6. Math.
   1. an equality between ratios; relationship between four quantities in which the quotient of the first divided by the second is equal to that of the third divided by the fourth (Ex.: 6 is to 2 as 9 is to 3)
      also called geometrical proportion
   2. rule of three

Etymology: ME proporcioun < MFr proporcion < L proportio < pro, for + portio, part: see portion

transitive verb

1. to cause to be in proper relation, harmony, or balance to proportion the punishment to the crime
2. to arrange the parts of (a whole) so as to be harmonious or properly balanced