Lacking continuity or contrary to the rule (9)
I believe the answer is:
irregular
'lacking continuity or contrary to the rule' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for irregular that I've seen before include "volunteer" , "Rough - guerrilla" , "unlike full-time soldiers" , "Not even or balanced" , "Against the rules" .)