Answer:

disuse

Answer	Crossword Clue
DISUSE	Cause of atrophy
DISUSE	Neglect
DISUSE	What obsolete things fall into

DISUSE	Fate of some old ways
DISUSE	Cessation of practice
DISUSE	Rust cause, perhaps
DISUSE	Obsolescence
DISUSE	Cessation of practice.
DISUSE	Inactivity.
DISUSE	Desuetude.
DISUSE	Something to fall into

DISUSE	What old things fall into
DISUSE	Toy fate
DISUSE	Abandonment
DISUSE	State of abandonment