Is the back of it over there in bed? (6)
I believe the answer is:
beyond
'is the back of it' is the definition.
I can't judge whether this defines the answer.
'over there in bed?' is the wordplay.
'over there' becomes 'yon' (archaic word meaning 'over there').
'in' means one lot of letters goes inside another.
'yon' going inside 'bed' is 'BEYOND'.
Can you help me to learn more?
(Other definitions for beyond that I've seen before include "(The) hereafter" , "Better than" , "Outside the range of" , "Farther along in space, time or degree" , "unknown" .)