dead giveaway

"I would not want to be seen with my father because of his darker skin and East African features were a dead giveaway," she told the BBC.

Coffee sprayed from my mouth, a dead giveaway that no, I’d never thought about latex.

However, for psychedelic RCTs, it can be difficult to properly blind participants — hallucinations are a bit of a dead giveaway.

Coffee sprayed from my mouth, a dead giveaway that no, I’d never thought about latex.

Even in blinded trials in which participants are not told which they received, ketamine's oftentimes trippy effects are a dead giveaway.