In back bedroom, point (3)
I believe the answer is:
nib
'point' is the definition.
(I know that nib is a type of point)
'in back bedroom' is the wordplay.
'back' shows that the letters should be reversed in order.
'bedroom' becomes 'b' (this could be a standard abbreviation of which I'm unaware).
'in' in reverse letter order is 'ni'.
'ni'+'b'='NIB'
Can you help me to learn more?
(Other definitions for nib that I've seen before include "Point of an old-fashioned pen" , "Pen-point" , "writer" , "Writing point of old pen" , "Writing tip of old pen" .)