q.l.adj. [ < the initial letters of classical Latin quantum libet as much as is desired < quantum which amount (see quantumn.) + libet it pleases (see libituden.)] rare ‘as much as is desired’.
ΚΠ
1890 G. M. GouldNew Med. Dict. 372/1Q.L., abbreviation of quantum libet—as much as desired.
1949 D. M. MacDonaldStudents' Pocket Prescriber (ed. 11) 305q.l. = quantum libet, enough.