lackluster is a valid English word

Scrabble validity: valid ( international - Sowpods, US - Twl06 )
iScramble validity: valid
QuickWords validity: valid

Meanings

Adjective (COMPARABLE)

Lacking brilliance or intelligence.
Having no shine or lustre; dull.
(figurative) Not exceptional; not worthy of special merit, attention, or interest; having no vitality.
• Synonym: Thesaurus:boring

Noun (COUNTABLE AND UNCOUNTABLE)

(uncountable) Lack of brightness or points of interest.
(countable) A person or thing of no particular brilliance or intelligence.

lackluster is a Scrabble valid word

lackluster

• International English (Sowpods) - The word is valid in Scrabble ✔
• US English (TWL06) - The word is valid in Scrabble ✔
• 00 points

lackluster is an iScramble, QuickWords valid word

lackluster

• The word is valid in iScramble ✔
• The word is valid in QuickWords ✔
• 00 points

Same letters words (Anagrams)

• LACKLUSTRE

Same letters plus one

• LACKLUSTERS
• LACKLUSTRES

Same letters minus one

• SCUTELLAR