fastness

Meanings

a rate (usually rapid) at which something happens
the quality of being fixed in place as by some firm attachment
a strongly fortified defensive structure

Synonyms

fixedness, fixity, fixture, secureness, speed, stronghold, swiftness

Scrabble Score: 11

fastness is a valid Scrabble (US) TWL word
fastness is a valid Scrabble Word in Merriam-Webster MW Dictionary
fastness is a valid Scrabble Word in International Collins CSW Dictionary

Words With Friends Score: 12

fastness is a valid Words With Friends word