Anxious to know about England's capital (4)
I believe the answer is:
keen
'anxious' is the definition.
(I've seen this before)
'know about england's capital' is the wordplay.
'know' becomes 'ken' (I've seen this in other clues).
'about' is an insertion indicator.
'capital' suggests taking the first letters.
The initial letter of 'englands' is 'e'.
'ken' enclosing 'e' is 'KEEN'.
'to' acts as a link.
(Other definitions for keen that I've seen before include "moan" , "Itching" , "Razor-edged" , "Enthusiastic or sharp" , "devoted" .)