Vessel from which a thousand eat (5)
I believe the answer is:
ketch
'vessel' is the definition.
(ketch is a kind of vessel)
'a thousand eat' is the wordplay.
'a thousand' becomes 'k' ('K' can be a synonym of 'thousand').
'eat' becomes 'etch' (I've seen this before).
'k'+'etch'='KETCH'
'from which' is the link.
(Other definitions for ketch that I've seen before include "Small two-master sailing vessel" , "Small sailing vessel with two masts" , "Jack" , "2-masted boat" , "The craft" .)