Rotter in river for some time (6)
I believe the answer is:
decade
'some time' is the definition.
The definition and answer can be both related to time as well as being singular nouns.
Maybe they are linked in a way I don't understand?
'rotter in river' is the wordplay.
'rotter' becomes 'cad' (I've seen this before).
'in' is an insertion indicator.
'river' becomes 'dee' (River Dee).
'cad' going inside 'dee' is 'DECADE'.
'for' is the link.
Can you help me to learn more?
(Other definitions for decade that I've seen before include "number of years" , "The 1960s, for example" , "Series of 10 years" , "The noughties, say" , "The noughties maybe" .)