Late volunteers dry off (5)
I believe the answer is:
tardy
'late' is the definition.
(I know that late can be written as tardy)
'volunteers dry off' is the wordplay.
'volunteers' becomes 'TA' (abbreviation for Territorial Army).
'off' is an anagram indicator.
'dry' anagrammed gives 'rdy'.
'ta'+'rdy'='TARDY'
(Other definitions for tardy that I've seen before include "Belated" , "Late - slow" , "Backward" , "Late, delayed" , "Behindhand" .)