'Valid' definitions:

Definition of 'valid'

(from WordNet)
adjective
Well grounded in logic or truth or having legal force; "a valid inference"; "a valid argument"; "a valid contract" [ant: invalid]
adjective
Still legally acceptable; "the license is still valid"

Definition of 'Valid'

From: GCIDE
  • Valid \Val"id\, a. [F. valide, L. validus strong, from valere to be strong. See Valiant.] [1913 Webster]
  • 1. Strong; powerful; efficient. [Obs.] "Perhaps more valid arms . . . may serve to better us." --Milton. [1913 Webster]
  • 2. Having sufficient strength or force; founded in truth; capable of being justified, defended, or supported; not weak or defective; sound; good; efficacious; as, a valid argument; a valid objection. [1913 Webster]
  • An answer that is open to no valid exception. --I. Taylor. [1913 Webster]
  • 3. (Law) Having legal strength or force; executed with the proper formalities; incapable of being rightfully overthrown or set aside; as, a valid deed; a valid covenant; a valid instrument of any kind; a valid claim or title; a valid marriage. [1913 Webster]
  • Syn: Prevalent; available; efficacious; just; good; weighty; sufficient; sound; well-grounded. [1913 Webster]

Synonyms of 'valid'

From: Moby Thesaurus