Glaring European, in conclusion, getting lost (9)
I believe the answer is:
engrossed
'lost' is the definition.
(thesaurus)
'glaring european in conclusion' is the wordplay.
'glaring' becomes 'gross' (synonyms).
'european' becomes 'E' (abbreviation e.g. EU).
'in' means one lot of letters goes inside another.
'conclusion' becomes 'end' (something's conclusion is its end).
'gross'+'e'='grosse'
'grosse' placed inside 'end' is 'ENGROSSED'.
'getting' acts as a link.
(Other definitions for engrossed that I've seen before include "Preoccupied" , "'Rapt, immersed (9)'" , "Deeply engaged" , "Wrapt, immersed" , "Son's greed (anag) - totally attentive" .)