Disease peculiar to coastal regions (7)
I believe the answer is:
seaside
'to coastal regions' is the definition.
I can't judge whether this defines the answer.
'disease peculiar' is the wordplay.
'peculiar' indicates an anagram (a peculiar or strange ordering of the letters).
'disease' is an anagram of 'SEASIDE'.
Can you help me to learn more?
(Other definitions for seaside that I've seen before include "Old song 'I do like to be beside the . . . . . . .'" , "Holiday place" , "Disease (anag) -- coast" , "Holiday destination" , "leisure area" .)