What does "hold water" mean?

To withstand scrutiny or criticism; to be valid.

Hold water

Common synonyms include: afford proof of, ascertain, be consistent, be demonstrable, be irrefutable, be logical.

verb

verb ·Rare ·Advanced level

Verb

1
To withstand scrutiny or criticism; to be valid. idiomatic
""Young man," he said, "upon this point I can only say that your story is grossly improbable. It won't hold water.""
2
resist or withstand wear, criticism, etc. wordnet

""Young man," he said, "upon this point I can only say that your story is grossly improbable. It won't hold water.""

Possibly from Jeremiah 2:13.