Is apprehensive about the boils? (7)
I believe the answer is:
seethes
'boils?' is the definition.
('seethe' can be a synonym of 'boil')
'is apprehensive about the' is the wordplay.
'is apprehensive' becomes 'sees' (I can't justify this - if you can you should believe this answer much more).
'about' indicates putting letters inside.
'sees' going around 'the' is 'SEETHES'.
Can you help me to learn more?
(Other definitions for seethes that I've seen before include "furious" , "is angry" , "gets agitated" , "is boiling" , "'Boils, with anger perhaps (7)'" .)