What does "permanent" mean?

Permanent: 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 impression. Eternity stands permanent and fixed. Dryden. Permanent gases (Chem. & Physics), hydrogen, oxygen, nitrogen, and carbon monoxide; -- also called incondensible or incoercible gases, before their liquefaction in 1877. -- Permanent way, the roadbed and superstructure of a finished railway; -- so called in distinction from the contractor's temporary way. -- 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. See Lasting.