Since feeding insatiable hunger, ready to swim the Channel? (7)
I believe the answer is:
greased
'hunger ready to swim the channel?' is the definition.
I can't tell whether this defines the answer.
'since feeding insatiable' is the wordplay.
'since' becomes 'as' (both can mean 'because').
'feeding' is an insertion indicator (one word is fed by another set of letters).
'insatiable' becomes 'greed' (I can't explain this - if you can you should believe this answer much more).
'as' going inside 'greed' is 'GREASED'.
Can you help me to learn more?
(Other definitions for greased that I've seen before include "As palms may be" , "well buttered" , "well lubricated" , "got moving with gun?" , "Oiled" .)