Roman emperor imprisoning five, getting us apprehensive (7)
I believe the answer is:
nervous
'apprehensive' is the definition.
('nervous' can be a synonym of 'apprehensive')
'roman emperor imprisoning five getting us' is the wordplay.
'roman emperor' becomes 'nero' (I've seen this before).
'imprisoning' means one lot of letters goes inside another.
'five' becomes 'v' (roman numeral).
'getting' says to put letters next to each other.
'nero' placed around 'v' is 'nervo'.
'nervo'+'us'='NERVOUS'
(Other definitions for nervous that I've seen before include "stewing" , "Fearful or apprehensive" , "Edgy" , "far from cool?" , "Highly strung" .)