valid

I

(New American Roget's College Thesaurus)

adj. sound, logical; legal, binding, well-grounded, just. See demonstration, truth, legality, power.

II

(Roget's IV) modif.

1. [Capable of proof]

Syn. sound, cogent, logical, conclusive, solid, well-grounded, well-founded, tested, accurate, convincing, telling, correct, determinative, compelling, persuasive, potent, stringent, strong, ultimate, unanswerable, irrefutable.

Ant. wrong*, erring, misleading.

2. [Genuine]

Syn. true, original, factual, real, actual, pure, uncorrupted, authentic, confirmed, authoritative, trustworthy, credible, attested, efficient, efficacious, legitimate, adequate, substantial, proved, proven, unalloyed, unadulterated.

Ant. false*, fictitious, counterfeit.

Syn.- valid applies to that which cannot be objected to because it conforms to law, logic, the facts, etc. [ a valid criticism, a valid license ] ; sound refers to that which is firmly grounded on facts, evidence, logic, etc. and is therefore free from error [ a sound method, a sound argument ] ; cogent implies such a powerful appeal to the mind as to appear conclusive [cogent reasoning ] ; convincing implies such validity as to persuade or overcome doubts or opposition [ a convincing performance ] ; telling suggests the power to have the required effect by being forcible, striking, relevant, etc. [ a telling rejoinder ]

III

(Roget's 3 Superthesaurus) a.

1. legal legitimate, authorized, certified, sanctioned, lawful, warranted, approved, authentic, genuine.

2. sound well-grounded, well-founded, solid, validated, logical, substantiated, correct, accurate, unassailable.

ANT.: 1. illegal, illegitimate, unauthorized, invalid. 2. flimsy, unsound, unproven

IV

(Roget's Thesaurus II) adjective 1. Based on good judgment, reasoning, or evidence: cogent, just, solid, sound2, tight, well-founded, well-grounded. See GOOD, REASON. 2. Worthy of belief, as because of precision or faithfulness to an original: authentic, authoritative, convincing, credible, faithful, true, trustworthy. See TRUE.