end·less \ˈen(d)lə̇s\adjective Etymology: Middle English endelees, from Old English endelēas, from ende end + -lēas -less — more at end, -less I 1.: having no end : boundless, infinite < endless duration > < an endless line > < endless praise > 2.: extremely numerous : very many < endless waves > < endless scraps > 3.: united at the ends so as to form a continuous whole < an endless chain > • end·less·lyadverb