fastness meaning and definition

FASTNESS noun

Definition of fastness (noun)

1. a rate (usually rapid) at which something happens
   • "the project advanced with gratifying speed"
   • synonyms: speed, swiftness
2. the quality of being fixed in place as by some firm attachment
   • synonyms: fixedness, fixity, fixture, secureness
   • antonym: looseness
3. a strongly fortified defensive structure
   • synonyms: stronghold