Adjective

(en adjective)

Well grounded or justifiable, pertinent.

*{{quote-magazine, year=2012, month=March-April

, author=(Jan Sapp) , title=Race Finished , volume=100, issue=2, page=164 , magazine=(American Scientist) citation , passage=Few concepts are as emotionally charged as that of race. The word conjures up a mixture of associations—culture, ethnicity, genetics, subjugation, exclusion and persecution. But is the tragic history of efforts to define groups of people by race really a matter of the misuse of science, the abuse of a valid biological concept?}}

I will believe him as soon as he offers a valid answer.

Acceptable, proper or correct.

A valid format for the date is MM/DD/YY.

Do not drive without a valid license.

Related to the current topic, or presented within context, relevant.

(logic) Of a formula or system: such that it evaluates to true regardless of the input values.

(logic) Of an argument: whose conclusion is always true whenever its premises are true.

An argument is valid if and only if the set consisting of both (1) all of its premises and (2) the contradictory of its conclusion is inconsistent.

Adjective

(er)

Untrue, not factual, factually incorrect.

*{{quote-book, year=1551, year_published=1888

, title= A New English Dictionary on Historical Principles: Founded Mainly on the Materials Collected by the Philological Society , section=Part 1, publisher=Clarendon Press, location=Oxford, editor= , volume=1, page=217 , passage=Also the rule of false position, with dyuers examples not onely vulgar, but some appertaynyng to the rule of Algeber.}}

Based on factually incorrect premises: false legislation

Spurious, artificial.

:

*

*:At her invitation he outlined for her the succeeding chapters with terse military accuracy?; and what she liked best and best understood was avoidance of that false modesty which condescends, turning technicality into pabulum.

(lb) Of a state in Boolean logic that indicates a negative result.

Uttering falsehood; dishonest or deceitful.

:

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

:

*(John Milton) (1608-1674)

*:I to myself was false , ere thou to me.

Not well founded; not firm or trustworthy; erroneous.

:

*(Edmund Spenser) (c.1552–1599)

*:whose false foundation waves have swept away

Not essential or permanent, as parts of a structure which are temporary or supplemental.

(lb) Out of tune.