Old ship under last bit of sail makes slow movement (5)
I believe the answer is:
largo
'slow movement' is the definition.
(I've seen this before)
'old ship under last bit of sail' is the wordplay.
'old ship' becomes 'argo' (I've seen this in other clues).
'under' says to put letters next to each other.
'last bit of' says to take the final letters.
The final letter of 'sail' is 'l'.
'argo' put after 'l' is 'LARGO'.
'makes' is the link.
(Other definitions for largo that I've seen before include "(Of music) broad and slow - Bond villain" , "Slow and dignified, like Handel's composition" , "To be played slowly and broadly" , "major key" , "Mus. slow movement" .)