Non-User
Black's Law Dictionary · Henry Campbell Black, M.A. · 1910
Black's Law Dictionary
Neglect to use. Neglect to use a franchise; neglect to exercise an office.
2 BL Comm. 153.
Neglect or omission to use an casement or other right.
3 Kent, Comm. 448.
A right acquired by use may be lost by non-user.