The definition I provided above has to do with the more figurative sense of the word, because I think we can all figure out what it means literally. So, here are a few more examples of watertight with the meaning above.
- Jeremiah must have a watertight alibi if he wants to be beyond suspicion.
- The contract is watertight, you don’t have to worry.
- That’s a pretty watertight argument, well done.
Can you think of any other examples?