(1):
(a.) Relating to, or securing, proportion.
(2):
(a.) Constituting a proportion; having the same, or a constant, ratio; as, proportional quantities; momentum is proportional to quantity of matter.
(3):
(a.) Having a due proportion, or comparative relation; being in suitable proportion or degree; as, the parts of an edifice are proportional.
(4):
(n.) Any number or quantity in a proportion; as, a mean proportional.
(5):
(n.) The combining weight or equivalent of an element.