Ship with only half a yard to move? (4)
I believe the answer is:
argo
'ship' is the definition.
(I've seen this before)
'only half a yard to move?' is the wordplay.
'only half' suggests halving the letters.
'a yard' becomes 'spar' (I've seen this before).
'to move?' becomes 'go' (going is a kind of moving).
'spar' halved is 'ar'.
'ar'+'go'='ARGO'
'with' is the link.
(Other definitions for argo that I've seen before include "Jason's legendary ship" , "Ship used by Jason in his search for the Golden Fleece" , "Ancient ship" , "Name of ship sailed by Jason in search of the Golden Fleece" , "Old sailing vessel" .)