Strange need to have large amount absorbed (9)
I believe the answer is:
engrossed
'absorbed' is the definition.
('engross' can be a synonym of 'absorb')
'strange need to have large amount' is the wordplay.
'strange' is an anagram indicator.
'to have' means one lot of letters goes inside another.
'large amount' becomes 'gross' (gross is a kind of amount. I am not sure about the 'large' bit.).
'need' with letters rearranged gives 'ened'.
'ened' enclosing 'gross' is 'ENGROSSED'.
Can you help me to learn more?
(Other definitions for engrossed that I've seen before include "occupied" , "Wrapt, immersed" , "Complete absorbed, rapt" , "Deeply engaged" , "'Rapt, immersed (9)'" .)