Meaning

• A quantity of something that is part of the whole amount or number.

• Harmonious relation of parts to each other or to the whole.

• Proper or equal share.

• The relation of one part to another or to the whole with respect to magnitude, quantity, or degree.

  "the proportion of the parts of a building, or of the body"

• A statement of equality between two ratios.

• The "rule of three", in which three terms are given to find a fourth.

• (chiefly in the plural) Size.

Meaning

• To divide into proper shares; to apportion.

• To form symmetrically.

• To set or render in proportion.

• To correspond to.