Designating an interval between two points in space-time that can in principle be observed to be separated only by time (that is, to occupy the same point in space as seen by a moving observer); relating to such an interval.
Events separated by time-like intervals are causally connected: there is enough time between them for light to pass from one to the other (they lie within each other's light-cones).
Early 20th century; earliest use found in Ludwik Silberstein (b. 1872). From time + -like.