Roget's 21st Century Thesaurus, Third Edition Copyright © 2013 by the Philip Lief Group.

WORD ORIGIN

late 14c., "pertaining to reason;" mid-15c., "endowed with reason," from Old French racionel and directly from Latin rationalis "of or belonging to reason, reasonable," from ratio (genitive rationis) "reckoning, calculation, reason" (see ratio).

MORE RELATED WORDS FOR NONRATIONAL

Roget's 21st Century Thesaurus, Third Edition Copyright © 2013 by the Philip Lief Group.