fastest is a valid English word

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

Meanings

Adjective

Superlative form of: fast
• He set a new fastest time for running a mile.

Adverb

Superlative form of: fast

Verb

second-person singular simple present indicative of fast
• But thou, when thou fastest, anoint thine head, and wash thy face.

fastest is a Scrabble valid word

fastest

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

fastest is an iScramble, QuickWords valid word

fastest

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

Same letters words (Anagrams)

• FASSETT
• SETFAST

Same letters plus one

• ARTFESTS
• ESTAFETS
• FASSETTS
• FAUSETTS
• FEASTEST
• SETFASTS
• STEDFAST

Same letters minus one

• FEASTS
• FESTAS
• SAFEST
• SATEST
• STATES
• TASSET
• TASTES
• TESTAS