untrue

Untrue, a.

1. Not true; false; contrary to the fact; as, the story is untrue.

2. Not faithful; inconstant; false; disloyal. Chaucer.

1 other Webster entry under this spelling

Untrue, adv.

Untruly. [Obs. or Poetic] Chaucer.

Shades of meaning

Fernald lists untrue only as an antonym, under faithful, honest, real.

He lists it without comment; the entries above explain its neighbors.

none given