spurious

adjective3

1. •
   False, not authentic, not genuine.

   • His argument was spurious and had no validity.
2. •
   Extraneous, stray; not relevant or wanted.

   • I tried to concentrate on the matter in hand, but spurious thoughts kept intruding.
   • Spurious emissions from the wireless mast were causing nearby electrical equipment to go haywire.
3. •
   (no longer used) Bastardly, illegitimate.

   • […] who also in her prime of love, Spousal embraces, vitiated with Gold, Though offer’d only, by the sent conceiv’d Her spurious first-born; Treason against me? — 1671