Moved slowly, finally summoned by hooter (5)
I believe the answer is:
nosed
'moved slowly' is the definition.
(nose can mean to move along quickly)
'finally summoned by hooter' is the wordplay.
'finally' says to take the final letters.
'by' is a charade indicator (letters next to each other).
'hooter' becomes 'nose' (informal term).
The last letter of 'summoned' is 'd'.
'd' put after 'nose' is 'NOSED'.
(Other definitions for nosed that I've seen before include "Nodes (anag.)" , "Beginner" , "smelt" , "Scented" , "proceeded slowly" .)