ETYM Latin permanens, -entis, p. pr. of permanere to stay or remain to the end, to last; per + manere to remain: cf. French permanent. Related to Per-, and Mansion.
1. Continuing or enduring without marked change in status or condition or place; SYN. lasting.
2. Not capable of being reversed or returned to the original condition.

A long-lasting hair wave or straightening produced by mechanical and chemical means — called also permanent wave