Staff not declaring (5)
I believe the answer is:
baton
'staff' is the definition.
(I've seen this before)
'not declaring' is the wordplay.
I cannot really see how this works, but
an anagram of 'not' is 'ton' which is located in the answer.
The remaining letters 'ba' is a valid word which might be clued in a way I don't understand.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for baton that I've seen before include "Short rod (that can be passed!)" , "A stick for a conductor and policeman" , "Relay runner's stick" , "Controller of players" , "Conductor wields it - or a policeman" .)