One detained by expression of admiration in meeting for discussion (6)
I believe the answer is:
powwow
'meeting for discussion' is the definition.
(I've seen this before)
'one detained by expression of admiration' is the wordplay.
'one detained' becomes 'POW' (prisoner of war).
'by' is a charade indicator (letters next to each other).
'expression of admiration' becomes 'wow' ('wow' is said in admiration).
'pow'+'wow'='POWWOW'
'in' is the link.
(Other definitions for powwow that I've seen before include "Huddle, summit" , "(Native American) conference or meeting" , "Meeting of Native Americans for discussion" , "American Indian conference" , "North American native ceremony" .)