Why bother turning up late? (5)
I believe the answer is:
tardy
'late?' is the definition.
(I know that late can be written as tardy)
'why bother turning up' is the wordplay.
'why' becomes 'y'.
'bother' becomes 'drat' (exclamation of annoyance).
'turning up' is a reversal indicator.
'y'+'drat'='ydrat'
'ydrat' written backwards gives 'TARDY'.
(Other definitions for tardy that I've seen before include "Belated" , "Late - slow" , "Late; sluggish" , "Late, delayed" , "Unpunctual" .)