The Collaborative International Dictionary of English v.0.48:
Permanent \Per"ma*nent\, a. [L. permanens, -entis, p. pr. of
permanere to stay or remain to the end, to last; per + manere
to remain: cf. F. permanent. See Per-, and Mansion.]
Continuing in the same state, or without any change that
destroys form or character; remaining unaltered or unremoved;
abiding; durable; fixed; stable; lasting; as, a permanent
Eternity stands permanent and fixed. --Dryden.
Permanent gases (Chem. & Physics), hydrogen, oxygen,
nitrogen, and carbon monoxide; -- also called
incondensible gases or incoercible gases, before their
liquefaction in 1877. The term is now archaic.
Permanent way, the roadbed and superstructure of a finished
railway; -- so called in distinction from the contractor's
Permanent white (Chem.), barium sulphate (heavy spar),
used as a white pigment or paint, in distinction from
white lead, which tarnishes and darkens from the
formation of the sulphide.
Syn: Lasting; durable; constant. See Lasting.