false

Etymology

From Middle English false, fals, from Old English fals (“false; counterfeit; fraudulent; wrong; mistaken”), from Latin falsus (“counterfeit, false; falsehood”), perfect passive participle of fallō (“deceive”). Reinforced in Middle English by Anglo-Norman and Old French fals, faus. Compare Scots fals, false, Saterland Frisian falsk, German falsch, Dutch vals, Swedish and Danish falsk; all from Latin falsus. Displaced native Middle English les, lese, from Old English lēas (“false”); See lease, leasing. Doublet of faux. The verb is from Middle English falsen, falsien, from Old French falser, from Latin falsō (“falsify”), itself also from falsus; compare French fausser (“to falsify, to distort”).

adj

1. Untrue, not factual, factually incorrect.
   Also the rule of false position, with dyuers examples not onely vulgar, but some appertaynyng to the rule of Algeber. 1551, James A.H. Murray, editor, A New English Dictionary on Historical Principles: Founded Mainly on the Materials Collected by the Philological Society], volume 1, Oxford: Clarendon Press, published 1888, Part 1, page 217, column 2
2. Based on factually incorrect premises.
   false legislation, false punishment
3. Spurious, artificial.
   false teeth
4. Uttering falsehood; dishonest or deceitful.
   a false witness
5. Not faithful or loyal, as to obligations, allegiance, vows, etc.; untrue; treacherous.
   a false friend, lover, or subject; false to promises
6. Not well founded; not firm or trustworthy; erroneous.
   a false conclusion; a false construction in grammar
7. Not essential or permanent, as parts of a structure which are temporary or supplemental.
8. 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 scorpion (an arachnid)
   false killer whale (a dolphin)
   false powderpost beetles (members of Bostrichidae not in Lyctinae)
9. (music) Out of tune.

verb

1. (electronics, telecommunications, of a decoder) To incorrectly decode noise as if it were a valid signal.
2. (obsolete) To violate, to betray (a promise, an agreement, one’s faith, etc.).
3. (obsolete) To counterfeit, to forge.
4. (obsolete) To make false, to corrupt from something true or real.

adv

1. In a dishonest and disloyal way; falsely.

noun

1. One of two options on a true-or-false test, that not representing true.
   The student received a failing grade for circling every true and false on her quiz.