1. (a.) 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.

2. (a.) Strong; powerful; efficient.

3. (a.) 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.

absolute acceptable actionable adducible admissible advantageous applicable armipotent attestative attested attestive auspicious authentic authoritative authorized based on beneficial benevolent binding bon bonny braw bueno capital certain circumstantial cogent commendable competent conclusive confirmed consistent constitutional convincing corroborated cumulative damning decisive definitive demonstrated determinative determined documentary documented dynamic effective effectual elegant energetic established estimable evidential evidentiary ex parte excellent expedient eye-witness factual fair famous favorable final fine firsthand forceful forcible founded on good goodly grand grounded on healthy hearsay helpful high-potency high-powered high-pressure high-tension implicit in force in power incontrovertible indicative indisputable irrefutable irresistible judicial juridical just justiciable kind kosher laudable lawful lawmaking legal legislative legit legitimate licit logical material mighty mighty in battle nice noble nuncupative operative overwhelming persuasive pleasant potent powerful prepotent presumptive probative profitable puissant regal reliable rightful royal ruling sanctioned satisfactory satisfying self-consistent significant skillful solid sound splendid statutory striking strong substantial substantiated sufficient suggestive sure symptomatic telling useful validated verified very good vigorous virtuous vital weighty well-founded well-grounded within the law