Make off, do a runner (7)
I believe the answer is:
abscond
I believe this is a double definition.
'make off' is the first definition.
(I've seen this before)
'do a runner' is the second definition.
(I've seen this before)
(Other definitions for abscond that I've seen before include "desert" , "cut and run" , "Leave hurriedly (to avoid arrest)" , "Leave quickly and secretly" , "Leave hurriedly to escape a legal process" .)