thrash about

to move unpredictably and often violently, usually unaware

Japanese Meaning

予測不能で激しい動き、無意識のうちに身体を振るう・暴れる

When the boat hit the waves, the trapped dolphin began to thrash about, attracting the rescuers' attention.

船が波に当たると、閉じ込められたイルカは激しくもがき始め、救助隊の注意を引いた。

Sense（1）

to move unpredictably and often violently, usually unaware

thrashes about

（ present singular third-person ）

thrashing about

（ participle present ）

thrashed about

（ participle past ）

thrashed about

（ past ）