Tangut character for gadfly

It names a biting fly.

Li Fanwen’s Tangut–Chinese dictionary glosses 𗪈 as “gadfly,” a fly that bites livestock. The script was created in the eleventh century for the Tangut language and Western Xia; historical accounts associate its creation with emperor Li Yuanhao and official Yeli Rengrong. The earliest surviving document cited by scholars dates to 1072, and a 1502 inscription shows use long after Western Xia fell. Tangut characters resemble Chinese characters, but belong to a distinct script. Scholars also compare Tangut structure with Khitan writing, another historical script; these are script-level links, not documented ties between 𗪈 and particular Chinese or Khitan characters.

What does it mean when someone sends 𗪈 alone?

The lone glyph cannot tell you why it was sent.

A reader trained in Tangut can recognize a word here; someone without that knowledge needs a translation or context. Sent alone, it may be a script sample or decoration. If the sender’s point matters, ask what they meant.