Don't declare! Stick! (5)
I believe the answer is:
baton
'stick' is the definition.
(term for a stick or staff)
I don't understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for baton that I've seen before include "Conductor's wand" , "Policeman's truncheon" , "Police (or conductor's) stick" , "Short rod (that can be passed!)" , "Stick passed in relay races" .)