perpetual calendar noun

1. A calendar by means of which it may be ascertained on which day of the week any given day has fallen or will fall
2. One which may be used for any year, or for more than a year

perpetual check noun

In chess, a situation in which one player's king is continually placed in check by the other player who may thereby claim a draw

perpetual curate noun

Formerly in the Church of England, an incumbent of a parish who had no endowment of tithes, since 1868 called a vicar

perpetual motion noun

A hypothetical machine, or motion of such a machine, that should do work indefinitely without an external source of energy

perpetual-moˈtionist noun

A believer in the possibility of perpetual motion

perpetual screw noun

An endless screw