Take off once, as a crow (6)
I believe the answer is:
avaunt
'take off once' is the definition.
I can't tell whether this definition defines the answer.
'a crow' is the wordplay.
'crow' becomes 'vaunt' (I've seen this in another clue).
'a'+'vaunt'='AVAUNT'
'as' acts as a link.
Can you help me to learn more?
(Other definitions for avaunt that I've seen before include "make tracks" , "Anything but a welcoming word!" , "Old word for be off" , "Shakespearian begone, move on" , "Leave" .)