adjective
valid
VAL-id/ˈvælɪd/
Acceptable as sound under the relevant rules or evidence.
The attendant lets her through the gate with a valid ticket.

Etymology
Latin validus describes strength or effectiveness. In English, this became legal force first, then the strength of an argument or claim sufficiently supported by facts or authority.
In context
a legal action is both valid and able to hold legal weight—not a law that has had to be overturned or rendered obsolete.
More examples
- Your license remains valid until the end of the year.
- She raises a valid concern about the cost.
- The conclusion is valid because the evidence supports it.
Forms
Similar words
- legitimate
- Emphasizes conformity to law or recognized authority, not reasoning.
- sound
- Emphasizes solid reasoning or evidence rather than official acceptance.