Well, look, hero is back in bed, getting end away (8)
I believe the answer is:
borehole
'well' is the definition.
Both the answer and definition are singular nouns.
Perhaps you can see a link between them that I can't see?
'look hero is back in bed getting end away' is the wordplay.
'look' becomes 'lo' (archaic exclamation meaning 'look!').
'is back' says the letters should be written backwards.
'in' indicates putting letters inside.
'getting end away' means to remove the last letter.
'lo'+'hero'='lohero'
'lohero' in reverse letter order is 'orehol'.
'bed' with its final letter taken away is 'be'.
'orehol' placed inside 'be' is 'BOREHOLE'.
Can you help me to learn more?
(Other definitions for borehole that I've seen before include "(A) deep drilling for oil, water" , "Deep excavation to find water" , "Something drilled to find water/oil" , "Narrow well" , "An excavation to reach groundwater" .)