This word is acceptable for play in the US & UK dictionaries that are being used in the following games:

• Lexulous
• Wordscraper
• Wordosaur

adj. Lacking brightness, luster, or vitality; dull. See Synonyms at dull.

adj. Lacking brilliance or intelligence

adj. Having no shine or lustre; dull

adj. Not exceptional; not worthy of special merit, attention, or interest; having no vitality

n. A lack of luster.

adj. Wanting luster or brightness.

adj. Lacking spirit, liveliness, or enthusiasm; dull.

adj. Mediocre.

Wanting luster or brightness; dull; languid; said of the eyes.

n. A want of luster, or that which lacks brightness.

adj. lacking luster or shine

adj. lacking brilliance or vitality

"Senate race in Massachusetts on what they described as a lackluster campaign."

dull    lacklustre   

dull    mediocre    bore   

unpublishable    thebus    reformers'    purple-black    unimpressive    doltish    withroyal    record-breaking    hard-to-find    stodgy