Twisted elastic on the sea's edge (9)
I believe the answer is:
coastline
'sea's edge' is the definition.
The answer and definition can be both locations as well as being singular nouns.
Perhaps they are linked in a way I don't understand?
'twisted elastic on' is the wordplay.
'twisted' is an anagram indicator.
'elastic'+'on'='elasticon'
'elasticon' is an anagram of 'COASTLINE'.
'the' acts as a link.
Can you help me to learn more?
(Other definitions for coastline that I've seen before include "Sea margin" , "Sectional (anag) - sea/land border" , "Perimeter of. eg. Britain" , "21 [SEASIDE]" , "Edge of a landmass" .)