"I cried aloud, shaking my head all the while until I felt the cold blades of scissors against my neck, and heard them gnaw off one my thick braids."
I know the general meaning of gnaw, but I'am not sure if it means the same here, and if it does in what exact sense?
(I have attached the paragraph from which the sentence is taken). Thanks to all who dedicate a small part of their life to help me out here :)