Anchor in bark’s stern-side (5)
I believe the answer is:
kedge
'anchor' is the definition.
(I've seen this before)
'bark's stern-side' is the wordplay.
'bark's stern' becomes 'k' (I can't justify this - if you can you should give a lot more credence to this answer).
'side' becomes 'edge' (edge is a kind of side).
'k'+'edge'='KEDGE'
'in' is the link.
Can you help me to learn more?
(Other definitions for kedge that I've seen before include "Small anchor" , "Lively" , "Light anchor" , "Use hawser" , "Move boat" .)