Ambulatory will
Black's Law Dictionary · Henry Campbell Black, M.A. · 1910
Black's Law Dictionary
A changeable will (ambulatoria voluntas), the phrase denoting the power which a testator possesses of altering his will during his life-time.
See Hattersiey v. Bis-sett, 50 N. J. Eq. 577, 25 Atl. 332