Adjective

(en adjective)

(of perception) Clear, detailed or powerful.

(of an image) Bright, intense or colourful.

*{{quote-book, year=1963, author=(Margery Allingham)

, title=(The China Governess) , chapter=1 citation , passage=The half-dozen pieces […] were painted white and carved with festoons of flowers, birds and cupids. To display them the walls had been tinted a vivid blue which had now faded, but the carpet, which had evidently been stored and recently relaid, retained its original turquoise.}}

Full of life, strikingly alive.

*{{quote-book, year=1907, author=

, title=The Dust of Conflict , chapter=32 citation , passage=The vivid , untrammeled life appealed to him, and for a time he had found delight in it; but he was wise and knew that once peace was established there would be no room in Cuba for the Sin Verguenza.}}

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.