High Barnet as American might call it (6)
I believe the answer is:
mohawk
'it' is the definition.
The definition suggests a singular noun which matches the answer.
I cannot understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for mohawk that I've seen before include "American native; skating step" , "Iroquoian American; skating manoeuvre" , "(N Amer.) Indian" , "Skating manoeuvre - member of Amerindian tribe" , "Brave" .)