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adj. fals·er, fals·est
1. Contrary to fact or truth: false tales of bravery.
2. Deliberately untrue: delivered false testimony under oath.
3. Arising from mistaken ideas: false hopes of writing a successful novel.
4. Intentionally deceptive: a suitcase with a false bottom; false promises.
5. Not keeping faith; treacherous: a false friend. See Synonyms at faithless.
6. Not genuine or real: false teeth; false documents.
7. Erected temporarily, as for support during construction.
8. Resembling but not accurately or properly designated as such: a false thaw in January; the false dawn peculiar to the tropics.
9. Music Of incorrect pitch.
10. Unwise; imprudent: Don't make a false move or I'll shoot.
11. Computers Indicating one of two possible values taken by a variable in Boolean logic or a binary device.
In a treacherous or faithless manner: play a person false.
[Middle English fals, from Old English, counterfeit, and from Old French, false, both from Latin falsus, from past participle of fallere, to deceive.]