Progressing while it's wet on Pen-y-ghent? (2,5)
I believe the answer is:
in train
'progressing' is the definition.
(in train means in progress)
'while it's wet on pen-y-ghent?' is the wordplay.
I cannot really see how this works, but
'wet' could be 'rain' (wet weather) and 'rain' is located in the answer.
'it' could be 't' (abbreviation. e.g. in 'tis) and 't' is present in the answer.
The remaining letters 'in' is a valid word which might be clued in a way I don't understand.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for in train that I've seen before include "happening?" , "using public transport" , "Being on board" , "Moving forward" , "On the move" .)