Level IV of XX on the frequency path
Frequency rank 451 / 2,608
Frequent enough that you will keep running into it once you read past headlines.
More common than 急 (Hurry), less common than 町 (Town).
You say (言) what is correct (正) — speaking the truth with correctness provides solid evidence.
証 is rank 451 of 2,608 in published Japanese.
Study 証 →