Live on edge (6)
I believe the answer is:
reside
'live' is the definition.
(I know that reside is a more specific form of the action live)
'on edge' is the wordplay.
'on' becomes 're' ('on' can be mean 'with reference to').
'edge' becomes 'side' (edge can mean the side of something).
're'+'side'='RESIDE'
(Other definitions for reside that I've seen before include "Occupy a place" , "Live in permanently" , "Dwell, be present (in)" , "Lodge" , "Live (at an address)" .)