Noah Webster
Valid
VAL'ID, adjective [Latin validus, from valeo, to be strong. The primary sense of the root is to strain or stretch.]
1. Having sufficient strength or force; founded in truth; sound; just; good; that can be supported; not weak or defective; as a valid reason; a valid argument; a valid objection.
2. Having legal strength or force; efficacious; executed with the proper formalities; that cannot be rightfully overthrown or set aside; supportable by law or right; as a valid deed; a valid covenant; a valid instrument of any kind; a valid claim or title; a valid marriage.
3. Strong; powerful; in a literal sense; as valid arms. [Not in use.]