▪ I.† ˈmensionObs.—0 [ad. L. mēnsiōn-em, n. of action to mētīri (ppl. stem mēns-) to measure.] The action of measuring. 1623Cockeram, Mension, a measuring.1658Phillips, Mensuration, the same as Mension, or measuring. ▪ II.mension obs. form of mention.