Military outpost hours away (5)
I believe the answer is:
forth
'away' is the definition.
(I know that away can be written as forth)
'military outpost hours' is the wordplay.
'military outpost' becomes 'fort' (a fort is a military post).
'hours' becomes 'h'.
'fort'+'h'='FORTH'
(Other definitions for forth that I've seen before include "Scottish river and firth" , "Onward; the Firth of - -" , "(Go) away" , "running into view" , "Water" .)