Bend old sail over that's small and elegant (5)
I believe the answer is:
bijou
'small and elegant' is the definition.
(term meaning small and elegant)
'bend old sail over' is the wordplay.
'bend' becomes 'U' (a U-bend is a kind of bend - pipe under sink).
'old' becomes 'o' (common abbreviation eg in OE for Old English).
'sail' becomes 'jib' (jibbing is a kind of sailing).
'over' says the letters should be written backwards.
'u'+'o'+'jib'='uojib'
'uojib' in reverse letter order is 'BIJOU'.
'that's' is the link.
(Other definitions for bijou that I've seen before include "(Of a house) small and elegant" , "Small and stylish" , "Small and delicate" , "Trinket; tiny and tasteful" , "Small, but elegant and tasteful" .)