いい加減

Etymology
Attested from the 18th century. Compound of, with sound shift from earlier.

Adjective

 * 1) sufficient, completely sufficient, enough
 * 2) irresponsible, groundless, inaccurate, halfhearted
 * 1) irresponsible, groundless, inaccurate, halfhearted

Usage notes
The contradictory senses may be distinguished in speech, with the “sufficient” sense pronounced as two words and the “halfhearted” sense as a single compound. In writing, the senses are not distinguished and may be ambiguous.

Noun

 * 1) (just) right
 * 2) moderate, appropriate
 * 1) moderate, appropriate