(transitive) To make something flat or flatter. / (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.

plural of flattening

Capable of being flattened.

Anything that flattens. / (finance) A trade whose terms are based on the assumption that the rate of return will decrease.

plural of flattener

The quality or degree of being flattenable.

Made flat by something.

simple past tense and past participle of flatten

present participle of flatten

The act, or the result of making something flat or flatter / A flattened part of something