Emily Dickinson Lexicon

I-SOCH'RON-AL, or I-SOCH'RON-OUS, a. [Gr. ισος, equal, and χρονος, time.]

Uniform in time; of equal time; performed in equal times. An isochronal line, is that in which a heavy body is supposed to descend without acceleration. Bailey. Isochronal vibrations of a pendulum are such as are performed in the same space of time. Encyc.