† inˈvolumentObs. [ad. late L. involūment-um (Vulgate), wrapper, f.involvĕre to involve: see -ment.] An envelope, covering. 1578Banister Hist. Man viii. 100 The hard Membran is both to the brayne an inuol[u]ment, as also an apt proppe.1657Tomlinson Renou's Disp. 278 That same tenuious involument is Mace.