fastness
1. [ noun ] the quality of being fixed in place
Synonyms: fixity secureness fixture fixedness
Related terms: immovability lodgment fasten
2. [ noun ] a rate (usually rapid) at which something happens
Synonyms: speed swiftness
Examples:

"the project advanced with gratifying speed"

Related terms: pace haste deceleration acceleration graduality execution_speed travel_rapidly rush accelerate slow fast
3. [ noun ] a strongly fortified defensive structure
Synonyms: stronghold
Related terms: defensive_structure keep hold blockhouse redoubt bastion
Similar spelling:   fast_one
  fasten
  fasting
  faction
  fastener
  fastened