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one shot; one charge; one explosion
one blow; one punch
home run
one try; one attempt
win on the first go-around after calling rīchi
ippatsu (comp. karuta); taking a card which is read immediately after sending it
一発で命中した。
It hit with one shot.
その銃には一発の弾があった。
There was one bullet in that gun.
彼は一発のパンチを繰り出した。
He threw one punch.