Synonyms: stronghold, fastness
Definition: a strongly fortified defensive structure
Similar words: defence, defense, defensive structure
Definition: a structure used to defend against attack
Usage: the artillery battered down the defenses
Synonyms: secureness, fixedness, fixity, fixture, fastness
Definition: the quality of being fixed in place as by some firm attachment
Similar words: immovability, immovableness
Definition: not capable of being moved or rearranged
Synonyms: fastness, speed, swiftness
Definition: a rate (usually rapid) at which something happens
Usage: the project advanced with gratifying speed
Definition: the relative speed of progress or change
Usage: he lived at a fast pace; he works at a great rate; the pace of events accelerated