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

WORD ORIGIN

c.1719, "that cannot be broken," from assimilated form of in- "not, opposite of" (see in- (1)) + refrangible.

MORE RELATED WORDS FOR IRREFRANGIBLE

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