Tangut character for “to drill”

Its dictionary sense is the Tangut verb “to drill.” If someone sent it alone, you can read the word; the reason for sending it still needs context.

Is 𘕭 a Chinese character?

No. It is a Tangut character in a separate script. Western Xia commissioned the Tangut script around 1036 as a national writing system, following neighboring Khitan rulers, who had created scripts of their own earlier. Its square design and character-building methods were inspired by Chinese writing, but Tangut is a distinct script. One likely goal was a Tangut collection of Buddhist scriptures; Tangut books also translated Chinese works, and writing continued after Western Xia fell.