The Collaborative International Dictionary of English v.0.48:
Perpetual \Per*pet"u*al\, a. [OE. perpetuel, F. perp['e]tuel,
fr. L. perpetualis, fr. perpetuus continuing throughout,
continuous, fr. perpes, -etis, lasting throughout.]
Neverceasing; continuing forever or for an unlimited time;
unfailing; everlasting; continuous.
Unto the kingdom of perpetual night. --Shak.
Perpetual feast of nectared sweets. --Milton.
Circle of perpetual apparition, or Circle of perpetual
occultation. See under Circle.
Perpetual calendar, a calendar so devised that it may be
adjusted for any month or year.
Perpetual curacy (Ch. of Eng.), a curacy in which all the
tithes are appropriated, and no vicarage is endowed.
Perpetual motion. See under Motion.
Perpetual screw. See Endless screw, under Screw.
Syn: Continual; unceasing; endless; everlasting; incessant;
constant; eternal. See Constant.