This is a pictograph of a spoked wheel. The round shape tells us that it functions as a wheel. Hence, it is the noun wheel.
Illustrative Text References:
Harappa: Stone Object: H-1506 A: Asko Parpola, B. M. Pande, and Petteri Koskikallio, 2010: Corpus of Indus Seals and Inscriptions: Volume 3,1: Page 202: New material, untraced objects, and collections outside India and Pakistan: Suomalainen Tiedeakatemia.
Mohenjo-daro: Seal: M-1103 a: Sayid Ghulam Mustafa Shah and Asko Parpola, 1991: Corpus of Indus Seals and Inscriptions: Volume 2: Page 116: Collections in Pakistan: Suomalainen Tiedeakatemia.
Mohenjo-daro: Seal: M-1718 a: Asko Parpola, B. M. Pande, and Petteri Koskikallio, 2010: Corpus of Indus Seals and Inscriptions: Volume 3,1: Page 27: New material, untraced objects, and collections outside India and Pakistan: Suomalainen Tiedeakatemia.
Comment:
In Indus inscription H-1506, Mahadevan's sign number 2651 is used as the noun vehicle.
Image Credit:
Indus Script Sign Number 2651: List of Sign Variants: Iravatham Mahadevan, 1977: The Indus Script: Texts, Concordance and Tables: The Director General Archaeological Survey of India.