Irritable, being on the fringes? (4)
I believe the answer is:
edgy
This clue is a double definition.
'irritable' is the first definition.
(I've seen this before)
'on the fringes?' is the second definition.
(on the edges)
'being' acts as a link.
(Other definitions for edgy that I've seen before include "Overstrung" , "ready to flap?" , "Sharp in outline" , "Nervous and tense, irritable" , "Keyed up" .)