false

1. One of two options on a true-or-false test.

   The student received a failing grade for circling every true and false on her quiz.

1. Untrue, not factual, factually incorrect.
2. Based on factually incorrect premises.

   false legislation, false punishment

3. Spurious, artificial.

   false teeth

4. Of a state in Boolean logic that indicates a negative result.
5. Uttering falsehood; dishonest or deceitful.

   a false witness

6. Not faithful or loyal, as to obligations, allegiance, vows, etc.; untrue; treacherous.

   a false friend, lover, or subject;  false to promises

7. Not well founded; not firm or trustworthy; erroneous.

   a false conclusion;  a false construction in grammar

8. Not essential or permanent, as parts of a structure which are temporary or supplemental.
9. Used in the vernacular name of a species (or group of species) together with the name of another species to which it is similar in appearance.

   false killer whale (a dolphin)

10. Out of tune.

adverb

In a dishonest and disloyal way; falsely.