Inspector concerned with craft heading the wrong way (5)
I believe the answer is:
rebus
'inspector' is the definition.
(I know that Rebus is a inspector)
'concerned with craft heading the wrong way' is the wordplay.
'concerned with' becomes 're' (re can mean regarding or about).
'craft' becomes 'sub' (sub is a kind of craft).
'heading the wrong way' is a reversal indicator.
'sub' in reverse letter order is 'bus'.
're'+'bus'='REBUS'
(Other definitions for rebus that I've seen before include "Word-picture puzzle" , "In Edinburgh, busy" , "Puzzle where pictures represent syllables and words" , "Ian Rankin's Scottish detective" , "Visual wordplay - Rankin's inspector" .)