Isochronal

from WordNet (r) 3.0 (2006)

isochronal
    adj 1: equal in duration or interval; "the oscillations were
           isochronal" [syn: {isochronal}, {isochronous}]

from The Collaborative International Dictionary of English v.0.48

Isochronal \I*soch"ro*nal\, a. [See {Isochronous}.]
   Uniform in time; of equal time; performed in equal times;
   recurring at regular intervals; as, isochronal vibrations or
   oscillations.
   [1913 Webster]