• (a.) Lasting but a moment; brief. • (a.) Of or pertaining to moment or momentum. • (a.) Important; momentous.
Mo·men'tal adjective [ Confer Old French momental .] [ Obsolete] 1. Lasting but a moment; brief. « Not one momental minute doth she swerve.» Breton. 2. Important; momentous. 3. (Mech.) Of or pertaining to moment or momentum.