Let anchors drift in port (10)
I believe the answer is:
charleston
'port' is the definition.
(I've seen this before)
'let anchors drift' is the wordplay.
'drift' indicates an anagram (I've seen 'drifting' mean this).
'let'+'anchors'='letanchors'
'letanchors' is an anagram of 'CHARLESTON'.
'in' acts as a link.
(Other definitions for charleston that I've seen before include "US city - 1920s' dance" , "Lively 1920s' dance" , "Dance making" , "Town of South Carolina which gave its name to a 1920s dance craze" , "Lively dance - then carols (anag)" .)