Tangut Character for “To Curse”

It means “to curse.” Li Fanwen’s dictionary gives that gloss for this entry; the numbered Unicode name is only an identifier.

Is 𘍅 Chinese or Tangut?

It is Tangut, not Chinese. In 1036, the Western Xia court promulgated the script for official use and Buddhist scripture. Tangut writing drew visual and structural ideas from Chinese without deriving from it; its creators also followed neighboring Khitan states, whose scripts appeared about a century earlier. Surviving manuscripts from the 12th and early 13th centuries include Buddhist and secular translations.