Etymology: Middle French or Medieval Latin; Middle French valide, from Medieval Latin validus, from Latin, strong, potent, from valēre
1. having legal efficacy or force; especially executed with the proper legal authority and formalities <a valid contract> 2. a. well-grounded or justifiable ; being at once relevant and meaningful <a valid theory> b. logically correct <a valid argument> <valid inference> 3. appropriate to the end in view ; effective <every craft has its own valid methods> 4. of a taxon conforming to accepted principles of sound biological classification • validity noun • validly adverb Synonyms: valid, sound, cogent, convincing, telling mean having such force as to compel serious attention and usually acceptance. valid implies being supported by objective truth or generally accepted authority <a valid reason for being absent> <a valid marriage>. sound implies a basis of flawless reasoning or of solid grounds <a sound proposal for reviving the economy>. cogent may stress either weight of sound argument and evidence or lucidity of presentation <the prosecutor's cogent summation won over the jury>. convincing suggests a power to overcome doubt, opposition, or reluctance to accept <a convincing argument for welfare reform>. telling stresses an immediate and crucial effect striking at the heart of a matter <a telling example of bureaucratic waste>.
New Collegiate Dictionary. 2001.