Deeply interested brothers sitting up in a bunk maybe (8)
I believe the answer is:
absorbed
'deeply interested' is the definition.
'absorbed' can be an answer for 'interested' (thesaurus). I am not certain of the 'deeply' bit.
'brothers sitting up in a bunk maybe' is the wordplay.
'brothers' becomes 'bros'.
'sitting up' shows that the letters should be reversed in order (in a down clue, letters go up).
'in' indicates putting letters inside.
'bunk maybe' becomes 'bed' (bunk bed).
'bros' reversed gives 'sorb'.
'a'+'bed'='abed'
'sorb' going inside 'abed' is 'ABSORBED'.
Can you help me to learn more?
(Other definitions for absorbed that I've seen before include "Wholly engrossed or imbued" , "Engrossed, immersed" , "Rapt, intent" , "Soaked up; rapt" , "Was a sponge" .)