This is a pictograph of an elephant. It is something very large that cannot be missed. Hence, the translation is the adverb obviously.
Illustrative Text Reference:
Mohenjo-daro: Seal: M-314 a: Jagat Pati Joshi and Asko Parpola, 1987: Corpus of Indus Seals and Inscriptions: Volume 1: Page 78: Collections in India: Suomalainen Tiedeakatemia.
Comments:
There is only one extant example of this sign in the Indus inscriptions. However, there are several elephant motifs on the Indus seals. An elephant motif carries the same meaning as the elephant sign.
Image Credit:
Elephant: Lynn Fawcett, 2017.