A line drawn on a map through all points having the same value of some measurable quantity.
thermodynamics A line in a phase diagram indicating the same mole fraction.
isotherm (plural isotherms)
A line of equal or constant temperature on a graph or chart, such as a weather map.
isohyet
A line drawn on a map connecting points that receive equal amounts of rainfall.
isochrone (Physical Geography) a line on a map or diagram connecting places from which it takes the same time to travel to a certain point
isotim
a line connecting points of equal transport costs. Intersecting isotims for multiple materials/products allow isodapanes to be drawn by connecting of the poin intersection