The Collaborative International Dictionary of English v.0.48:

Equant \E"quant\, n. [L. aequans, -antis, p. pr. of aequare: cf.
   F. ['e]quant. See Equate.] (Ptolemaic Astron.)
   A circle around whose circumference a planet or the center of
   ann epicycle was conceived to move uniformly; -- called also
   eccentric equator.
   [1913 Webster]