proportionable

adjective

pro·​por·​tion·​able prə-ˈpȯr-sh(ə-)nə-bəl 

: proportional, proportionate

proportionably

prə-ˈpȯr-sh(ə-)nə-blē 

adverb archaic

Word History

Etymology

Middle English proporcionable, borrowed from Middle French & Late Latin; Middle French, borrowed from Late Latin prōportiōnābilis, re-formation of prōportiōnālis proportional entry 2, perhaps after Latin ratiōnābilis "rational, reasonable" — more at -able

First Known Use

14th century, in the meaning defined above