The Collaborative International Dictionary of English v.0.48:

Equidistant \E`qui*dis"tant\, a. [L. aequidistans, -antis;
   aequus equal + distans distant: cf. F. ['e]quidistant.]
   Being at an equal distance from the same point or thing. --
   E`qui*dis"tant*ly, adv. --Sir T. Browne.
   [1913 Webster]

WordNet (r) 3.0 (2006):

equidistant
    adj 1: the same distance apart at every point

Moby Thesaurus II by Grady Ward, 1.0:

48 Moby Thesaurus words for "equidistant":
   aligned, amidships, analogous, average, center, centermost,
   central, coextending, coextensive, collateral, concurrent, core,
   equal, equatorial, equispaced, even, halfway, interior,
   intermediary, intermediate, lined up, mean, medial, median,
   mediocre, mediterranean, medium, mesial, mezzo, mid, middle,
   middlemost, middling, midland, midmost, midships, midway,
   nonconvergent, nondivergent, nuclear, parallel, parallelepipedal,
   parallelinervate, paralleling, parallelodrome, parallelogrammatic,
   parallelogrammic, parallelotropic