One Manx cat in suffering, coiled up (7)
I believe the answer is:
helical
'coiled up' is the definition.
'helical' can be an answer for 'coiled' (I've seen this in another clue). I'm unsure of the 'up' bit.
'one manx cat in suffering' is the wordplay.
'one' becomes 'i' (Roman numeral).
'manx' means to remove the last letter (the word has no 'tail', like a Manx cat).
'in' is an insertion indicator.
'suffering' becomes 'hell' (hell can mean a terrible ordeal).
'cat' with its last letter removed is 'ca'.
'i'+'ca'='ica'
'ica' going within 'hell' is 'HELICAL'.
Can you help me to learn more?
(Other definitions for helical that I've seen before include "Curled like corkscrew" , "In the form of a spiral" , "Like a spiral or spring" , "Like the pattern on a snail's shell" , "Spiral-shaped" .)