n. An isoline on a map or chart connecting points that have the same value of a quantity that has dimension time.
n. A semicubical parabola
The Century Dictionary and Cyclopedia
n. A line connecting points at which the same events occur simultaneously.
n. Specifically In hydrol., the line bounding an area of watershed whose river-flow will concentrate in a given time at a central point to form a flood.
WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.
n. an isogram connecting points at which something occurs or arrives at the same time
Word Usage
"Isochrone Maps in Google Maps - Google Maps Mania links to resources on how to create an isochrone map - i.e., a map that shows travel time from a given point by drawing lines like topographic contours - within the Google Maps environment."