Definition of: valid

(val′id) adjective
1. Based on evidence that can be supported; sound; just; sufficient and effective in law.
2. Obs. Strong.
3. Stat. Having a high degree of correlation with its criterion: distinguished from reliable. [<F valide <L validus powerful <valere be strong]
—val′id·ly adverb
—val′id·ness noun Synonyms: cogent, conclusive, convincing, efficacious, efficient, good, incontestable, irrefragable, irrefutable, just, logical, solid, sound, substantial, sufficient, undeniable, weighty. See POWERFUL. Antonyms: see synonyms for VAIN.