Nervous -- and imperfect, perhaps? (5)
I believe the answer is:
tense
I believe this is a double definition.
'nervous' is the first definition.
('tense' can be similar in meaning to 'nervous')
'imperfect perhaps?' is the second definition.
(imperfect is a kind of tense)
'and' acts as a link.
(Other definitions for tense that I've seen before include "Under emotional strain" , "Uneasy" , "(Of muscle) tight" , "Taut - timely verbal indication" , "not together?" .)