|1.||the dimension of time, which is necessary in addition to three spatial dimensions to specify fully the position and behaviour of a point or particle|
|2.||the concept in science fiction of a dimension in addition to three spatial dimensions, used to explain supernatural phenomena, events, etc|
|fourth dimension (fôrth) Pronunciation Key
Time regarded as a coordinate dimension. A fourth dimension is required by relativity theory, along with three spatial dimensions, to specify completely the location of any event.