**Pro*por"tion*al** (?), a. [L. *proportionalis*: cf. F. *proportionnel*.]

**1.**

Having a due proportion, or comparative relation; being in suitable proportion or degree; as, the parts of an edifice are **proportional**.

*Milton.*

**2.**

Relating to, or securing, proportion.

*Hutton.*

3. Math. Constituting a proportion; having the same, or a constant, ratio; as, **proportional** quantities; momentum is **proportional** to quantity of matter.

Proportional logarithms, logistic logarithms. See under Logistic. -- Proportional scale, a scale on which are marked parts proportional to the logarithms of the natural numbers; a logarithmic scale. -- Proportional scales, compasses, dividers, etc. Draughting, instruments used in making copies of drawings, or drawings of objects, on an enlarged or reduced scale.

© Webster 1913.

**Pro*por"tion*al**, n.

**1.** Math.

Any number or quantity in a proportion; as, a mean **proportional**.

**2.** Chem.

The combining weight or equivalent of an element.

[Obs.]

© Webster 1913.