The Indus Dictionary Project
This is a pictograph of an adult person holding a measuring rod. The point of light between his legs indicates relative stature. He is the most senior or chief person with a measuring rod. This usage of the point of light shares a common root with the modern Chinese character tài 太.
Someone whose profession was centred around measurement would have been a carpenter. Hence, Mahadevan's sign number 20 can be interpreted as chief carpenter, which in modern terms becomes the noun architect.
Mohenjo-daro: Seal: M-704 a: Sayid Ghulam Mustafa Shah and Asko Parpola, 1991: Corpus of Indus Seals and Inscriptions: Volume 2: Page 42: Collections in Pakistan: Suomalainen Tiedeakatemia.
There are no other surviving examples of this Indus sign.
Indus Script Sign Number 20: Sign List of the Indus Script: Iravatham Mahadevan, 1977: The Indus Script: Texts, Concordance and Tables: The Director General Archaeological Survey of India.