Anxious period guarding the Queen? On the contrary (5)
I believe the answer is:
eager
'anxious' is the definition.
(eg being anxious to begin something)
'period guarding the queen? on the contrary' is the wordplay.
I cannot really see how this works, but
'period' could be 'age' (age is a kind of period) and 'age' is present in the answer.
'queen?' could be 'er' (abbreviation for Elizabeth Regina) and 'er' is found within the answer.
No letters remain.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for eager that I've seen before include "really keen" , "Enthusiastic, raring to go" , "Thirsty" , "willing" , "Swiss mountain" .)