vt.

1. 使平坦；弄平
   The workman flattened a piece of metal by hammering it.

   工匠將一塊金屬錘平。

2. 擊倒，擊敗；摧毀
   The storm flattened the crops.

   暴風雨使莊稼都倒下來了。

vi.

1. 變平坦[（+out）]
   The lump had almost flattened out.

   這腫塊差不多消失了。

v.

1. make or become flat or flatter.
2. press (oneself) against a surface.
3. raze to the ground.
4. informal strike (someone) so as to make them fall down.
5. Music  lower (a note) in pitch by a semitone.