Anxious to be perfect, say (5)
I believe the answer is:
tense
This clue is a double definition.
'anxious' is the first definition.
(I've seen this in another clue)
'be perfect say' is the second definition.
(I've seen this in another clue)
'to' acts as a link.
(Other definitions for tense that I've seen before include "Taut - timely verbal indication" , "Maybe future" , "Rigid, or grammatical time" , "Drawn" , "Could be present" .)