Jeer in greeting ship (4)
I believe the answer is:
hiss
'jeer' is the definition.
(thesaurus)
'greeting ship' is the wordplay.
'greeting' becomes 'hi' (hi is a kind of greeting).
'ship' becomes 'ss'.
'hi'+'ss'='HISS'
'in' is the link.
(Other definitions for hiss that I've seen before include "less welcome sign?" , "Snake's sibilant sound" , "Wordless sound of disapproval" , "Boo" , "Audio interference" .)