Added 9 October 2026 lackluster /ˈlæklʌstə/ adjective Categories: Describing WordsRare Words adjective ! Definition from WordNet 3.1, Princeton University. Pronunciation from Wiktionary, via Kaikki.org. More about lackluster at Wordnik → Where our words come from → Lacking brilliance or vitality. a dull lackluster life Lacking luster or shine. staring with lackluster eyes Related Words: lacklustrelustrelesslusterlessdulllifelessmediocreweakmutedpoorsluggishdrabvulnerable Back to today's word