How do Jack and Jill deteriorate? (2,8)
I believe the answer is:
go downhill
'deteriorate?' is the definition.
(I've seen this before)
'how do jack and jill' is the wordplay.
I cannot really understand how this works, but
'do' is present in the answer.
'and' could be 'n' (common abbreviation for 'and') and 'n' is located in the answer.
an anagram of 'how' is 'owh' which is within the remaining letters.
The remaining letters 'gill' is a valid word which might be clued in a way I don't see.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for go downhill that I've seen before include "take part in skiing event" , "Decline" , "Ski" , "fall" , "Skiers will usually" .)