The Indus Dictionary Project
This is the noun lane with the adjective large in the centre. The translation is wide lane.
Mohenjo-daro: Tablet: M-1425 A: Sayid Ghulam Mustafa Shah and Asko Parpola, 1991: Corpus of Indus Seals and Inscriptions: Volume 2: Page 193: Collections in Pakistan: Suomalainen Tiedeakatemia.
It is interesting to note that each of the inscriptions with examples of this sign, also includes another symbol that gives us some indication of how wide the lane actually was, either a pictograph of a porter with a carrying pole, or a measuring rod with spaces for the number of units of measurement.
Indus Script Sign Number 1117: List of Sign Variants: Iravatham Mahadevan, 1977: The Indus Script: Texts, Concordance and Tables: The Director General Archaeological Survey of India.