Perverse high lunar tide swamping loch (3-7)
I believe the answer is:
ill-natured
'perverse' is the definition.
Both the answer and definition are adjectives. Maybe you can see a link between them that I don't see?
'high lunar tide swamping loch' is the wordplay.
'high' is an anagram indicator (like drunk).
'swamping' means one lot of letters goes inside another (swamp can mean to surround or smother).
'loch' becomes 'l'.
'lunar'+'tide'='lunartide'
'lunartide' is an anagram of 'ilnatured'.
'ilnatured' enclosing 'l' is 'ILL-NATURED'.
Can you help me to learn more?
(Other definitions for ill-natured that I've seen before include "Bad-tempered, churlish" , "Mean-spirited" .)