This ideograph is based on a street plan in which two roads converge in the top corner. Therefore, it is the compound noun street corner.
Illustrative Text Reference:
Harappa: Tablet in bas-relief: H-201 A: Jagat Pati Joshi and Asko Parpola, 1987: Corpus of Indus Seals and Inscriptions: Volume 1: Page 212: Collections in India: Suomalainen Tiedeakatemia.
Comment:
It should be noted that the layout follows that of the streets shown in the symbol for a city.
Image Credit:
Indus Script Sign Number 135: Sign List of the Indus Script: Iravatham Mahadevan, 1977: The Indus Script: Texts, Concordance and Tables: The Director General Archaeological Survey of India.