Geese formation
I believe the answer is:
vee
'geese formation' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for vee that I've seen before include "22nd letter of the alphabet" , "Shape resembling the twenty-second letter" , "Letter; notch shape" , "Character" , "Angled mark or notch" .)