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

WORD ORIGIN

1590s, "not limited in extent," from un- (1) "not" + past participle of bound (v.1). Sense of "generous, profuse, liberal" is recorded from 1704.

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