Shelter penetrated by river, one rising on Biddulph Moor (5)
I believe the answer is:
trent
'one rising on biddulph moor' is the definition.
The definition suggests a singular noun which matches the answer.
'shelter penetrated by river' is the wordplay.
'shelter' becomes 'tent' (canvas shelter).
'penetrated by' is an insertion indicator (I've seen this in other clues).
'river' becomes 'r' (abbreviation for river).
'tent' placed around 'r' is 'TRENT'.
Can you help me to learn more?
(Other definitions for trent that I've seen before include "Eng. river; Council of -" , "Stoke's river" , "Nottingham's river" , "Main river of the Midlands" , "Crossword frame" .)