Conscious and excited about new obligation (8)
I believe the answer is:
sentient
'conscious' is the definition.
(similar in meaning)
'excited about new obligation' is the wordplay.
'excited' becomes 'sent' (send can mean to excite or stimulate).
'about' is an insertion indicator.
'new' becomes 'n' (common abbreviation eg NT for New Testament).
'obligation' becomes 'tie' (I've seen this before).
'n'+'tie'='ntie'
'sent' enclosing 'ntie' is 'SENTIENT'.
'and' acts as a link.
(Other definitions for sentient that I've seen before include "Having feelings" , "Capable of feeling things as in tenets" , "Endowed with feeling and consciousness" , "having power of perception" , "Feeling, conscious" .)