Incontestable (5 letters)

{ Answer }

VALID

{ Related Clues }

Authenticated
Certified
Cogent
Convincing
In effect
Good
Lawful
Legal
Legitimate
Sound
Supportable
True
Bona fide
Legally binding
Sound, as an excuse
Still in effect
Tried and true
Well-founded
Good, as a driver's license
Having legal force
Like a good excuse
Not yet expired

{ Tags }

convincing, drivers, effect, excuse, expired, fide, force, founded, good, having, incontestable, legal, license, like, not, sound, tried, true, valid, well, yet

{ Notes }

The answer VALID is uncommon, appearing about once every 425 puzzles.

{ Definition }

VALID as an adjective:

1. well grounded in logic or truth or having legal force; "a valid inference"; "a valid argument"; "a valid contract"; "a valid license"

2. still legally acceptable; "the license is still valid"