Truant GI (4)
I believe the answer is:
awol
'truant gi' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for awol that I've seen before include "On the lam" , "Not present when supposed to be" , "Truant (or just missing)" , "Absent without leave (abbr.)" , "Absent without leave (abbrev.)" .)