Eastern harbour looks up - a figure of speech (5)
I believe the answer is:
trope
'a figure of speech' is the definition.
(trope can mean a figure of speech)
'eastern harbour looks up' is the wordplay.
'eastern' becomes 'e'.
'harbour' becomes 'port' (I've seen this before).
'looks up' shows that the letters should be reversed in order (I've seen 'looking up' mean this (in a down clue, letters go up)).
'e'+'port'='eport'
'eport' in reverse letter order is 'TROPE'.
(Other definitions for trope that I've seen before include "Image, figure of speech" , "Metaphorical use of a word or expression" , "figuratively speaking" , "Word used in a figurative sense" , "in a manner of speaking?" .)