1. The quality of being fixed and unchangeable
   "the fixedness of his gaze upset her";
   - unalterability
    
2. The quality of being fixed in place as by some firm attachment
   "The fixedness of his gaze was unnerving";
   - fastness, fixity, fixture, secureness
    
3. Remaining in place
   "The fixedness of the guard was impressive";
   - stationariness, immobility

Type of: changelessness, immovability, immovableness, lifelessness, motionlessness, stillness, unchangeability, unchangeableness, unchangingness

Antonym: looseness