This is a pictograph of a pair of calipers. Calipers are used to measure the distance between two opposite sides of an object. Hence, this Indus sign is an ideograph for the noun diameter.
The symbol is related to the Chinese character jiōng 冂. Jiōng can be translated as outer limits or wide.
Illustrative Text Reference:
Kalibangan: Seal: K-40 a: Jagat Pati Joshi and Asko Parpola, 1987: Corpus of Indus Seals and Inscriptions: Volume 1: Page 305: Collections in India: Suomalainen Tiedeakatemia.
Comments:
Please note that the elephant motif on the seal impression K-40 a has its head facing left. Therefore, the inscription is read from left to right.
In the context of inscription K-40, a good translation for this symbol might be the noun girth or barrel.
Image Credit:
Diameter: Lynn Fawcett, 2018.