Entry 1 sense Webster, 1913 Glooming · Gloom·ing · IPA 01 n. Twilight (of morning or evening); the gloaming. 1. Twilight (of morning or evening); the gloaming. “When the faint glooming in the sky First lightened into day.” — Trench. “The balmy glooming, crescent-lit.” — Tennyson.