This is a pictograph of a row of six teeth. The six teeth represent canine incisors. Hence, this Indus symbol is the noun incisors.
Illustrative Text Reference:
Ur: Stamp seal: Museum Number 122847: British Museum Collection Online: http://www.britishmuseum.org/research/collection_online/collection_object_details.aspx?objectId=805148&partId=1&searchText=indus+seal&page=1: Accessed: 27 October 2018.
Comment:
In the inscription from Ur, the row of six incisors is followed by the guard dog pictograph. In context, it therefore refers to a dog's teeth. However, other mammals also have a row of six incisors. Thus, it may be that in practice, this symbol was used to refer to the bites of other animals in addition to dogs.
Image Credit:
Indus Script Sign Number 9832: List of Sign Variants: Iravatham Mahadevan, 1977: The Indus Script: Texts, Concordance and Tables: The Director General Archaeological Survey of India.