Condemn one to be removed from consciousness (8)
I believe the answer is:
sentence
'condemn' is the definition.
('sentence' can be a synonym of 'condemn')
'one to be removed from consciousness' is the wordplay.
'one' becomes 'i' (Roman numeral).
'to be removed from' is a deletion indicator.
'consciousness' becomes 'sentience' (sentience is a kind of consciousness).
'sentience' with 'i' taken away is 'SENTENCE'.
(Other definitions for sentence that I've seen before include "That which ends with a full stop" , "Period of imprisonment" , "that may be penned?" , "life perhaps" , "Pass judgement on" .)