a. [ Holo + Gr. &unr_;, &unr_;, light. ] (Opt.) Causing no loss of light; -- applied to reflectors which throw back the rays of light without perceptible loss. [ 1913 Webster ]
{ , a. [ Poly- + Gr. &unr_;, &unr_;, light. ] (Elec.) Pertaining to or designating arc lamps so constructed that more than one can be used on a single circuit. [ Webster 1913 Suppl. ]