Flatten (verb)

1. Make flat or flatter.
2. Collapse or fall to the ground.
3. Press down or smooth (something) with a flat object or surface.

Origin:

Late middle english: from middle low german vlatten, frequentative of vlat "smooth".

Examples:

1. She flattened the dough with a rolling pin.
2. The building was flattened by the explosion.
3. The steamroller was used to flatten the road.
4. The wind flattened the tall grass.
5. She flattened the creases in the shirt with her hands.