A poster designed for a coastal place (7)
I believe the answer is:
seaport
'a coastal place' is the definition.
The answer and definition can be both locations as well as being singular nouns.
Maybe there's an association between them I don't understand?
'a poster designed' is the wordplay.
'designed' indicates an anagram (designed with the letters).
'a'+'poster'='aposter'
'aposter' is an anagram of 'SEAPORT'.
'for' is the link.
Can you help me to learn more?
(Other definitions for seaport that I've seen before include "Town with deep-water harbour" , "Liverpool" , "Lisbon, for example" , "Town with a large harbour" , "Dover, say" .)