Left port, unhappy about a wicked lie (6)
I believe the answer is:
sailed
'left port' is the definition.
(I've seen this in another clue)
'unhappy about a wicked lie' is the wordplay.
'unhappy' becomes 'sad' (associated in meaning).
'about' is an insertion indicator.
'a wicked' indicates an anagram.
'lie' is an anagram of 'ile'.
'sad' going around 'ile' is 'SAILED'.
(Other definitions for sailed that I've seen before include "Travelled by wind over water" , "Travelled by boat" .)