dimension (n.)

late 14c., dimensioun, "measurable extent, magnitude measured along a diameter," from Latin dimensionem (nominative dimensio) "a measuring," noun of action from past-participle stem of dimetri "to measure out," from dis- (see dis-) + metiri "to measure," from PIE root *me- (2) "to measure."

Sense of "bulk, size, extent, or capacity" is from 1520s, Meaning "any component of a situation" is from 1929. Related: Dimensional; dimensions.