ultramarine UK /ˌʌltɹəməˈɹiːn/US /ˌəltɹəməˈɹin/adjective 2noun 2forms 3 adjective2 •Of a brilliant dark blue or slightly purplish color like that of the pigment. •(no longer used) Beyond the sea. noun2 •In full ultramarine blue: a brilliant blue pigment traditionally made from ground-up lapis lazuli, and now usually either extracted from mineral deposits or made synthetically. •A brilliant dark blue or slightly purplish colour like that of the pigment.The atmosphere beneath is languorous, and is so tinged with azure that what artists call the middle distance partakes also of that hue, while the horizon beyond is of the deepest ultramarine. — 1891 formsultramarines · more ultramarine · most ultramarine