動詞 flatten:

1. make flat or flatter
2. become flat or flatter
   同義詞：flatten out
3. lower the pitch of (musical notes)
   同義詞：drop

1. Flatten the dough with a press of the hand.
   用手把生面團壓平。
2. The graph flattens out gradually after a steep fall.
   圖表上的曲線突降之後逐漸趨於平穩(wěn)。
3. The land flattens out near the coast.
   海岸附近地勢變得很平坦。
4. He was totally flattened by her sarcasm.
   她說的挖苦話使他無地自容。

flat.ten

v.（動詞）
flat.tened,flat.ten.ing,flat.tens
v.tr.（及物動詞）
To make flat or flatter.
把…弄平：使變平或變得更平
To knock down; lay low:
擊倒；把…放低：
例句：
The boxer was flattened with one punch.
那個拳擊手被一拳擊倒了

v.intr.（不及物動詞）
To become flat or flatter.
變平或變得更平

【引伸】
flat.tener
n.（名詞）