validity

noun

1 it is time to examine the validity of this argument:

soundness, reasonableness, rationality, logic, justifiability, defensibility, sustainability, plausibility, viability, bona fides, effectiveness, cogency, power, credibility, believability, force, strength, weight, foundation, substance, substantiality, authority, reliability.

▷antonyms invalidity.

2 the judges have recognized the validity of the contract:

legal acceptability, authenticity, correctness, bona fides, genuineness;

lawfulness, legality, legitimacy, binding nature, contractual nature;

force, effect, effectiveness.

validity Oxford Dictionary of English