flatten

1. (transitive) To make something flat or flatter.Examples: "As there was a lot of damage, we chose the heavy roller to flatten the pitch."; "Mary would flatten the dough before rolling it into pretzels."; "Attempting to block the police van's path, protesters periodically surrounded the vehicle and eventually flattened one of its tires."transitive

2. (reflexive) To press one's body tightly against a surface, such as a wall or floor, especially in order to avoid being seen or harmed.Examples: "With a bolt of fright he remembered that there was no bathroom in the Hob-house Room. He leapt along the corridor in a panic, stopping by the long-case clock at the end where he flattened himself against the wall."reflexive

3. (transitive) To knock down or lay low.Examples: "The prize fighter quickly flattened his challenger."transitive

4. (intransitive) To become flat or flatter; to plateau.Examples: "Prices have flattened out."intransitive

5. (intransitive) To be knocked down or laid low.intransitive

6. (music) To lower by a semitone.