1 [cartography] A line on a map connecting points of equal elapsed time; especially, travel time to or from a given location.
2 [cartography] A line on a map connecting points at which an event occurs, or a state of affairs exists, at the same time.
1 [cartography] A line on a map connecting points of equal elapsed time; especially, travel time to or from a given location.
2 [cartography] A line on a map connecting points at which an event occurs, or a state of affairs exists, at the same time.