The Collaborative International Dictionary
Tautochronous
Tautochronous \Tau*toch"ro*nous\, a. (Math.) Occupying the same time; pertaining to, or having the properties of, a tautochrone.
Wiktionary
tautochronous
a. 1 Occupying the same time. 2 (context mathematics English) Relating to, or having the properties of, a tautochrone.