一発・１発|いっぱつippatsu[4]odaka (tail-high)

1. nounone shot; one charge; one explosion
2. nounone blow; one punch
   トムは頭あたまにきつい一いち発はつを受うけた。↗

   Tom received a heavy blow on the head.
3. noun, baseballhome run
4. noun, adverbone try; one attempt
5. noun, mahjongwin on the first go-around after calling rīchi
6. noun, card gamesippatsu (comp. karuta); taking a card which is read immediately after sending it

• Synonym一撃いちげきNeutralA single blow or attack, as in 「一撃で倒す」; in climbing it also means on-sight. 「一発」 is colloquial and also covers one shot or doing something in one go.
• Synonym弾薬の一発NeutralA phrase for one round of ammunition, stressing the ammo count in an explanatory way; 「一発」 also means a blow or a single attempt.
• RelatedヒットNeutralLoanword for a baseball base hit or a work that takes off; in baseball 「一発」 means a home run, and more broadly it just counts one attempt.
• Related命中めいちゅうWrittenA written, formal-leaning noun for a bullet or arrow striking the target; 「一発」 counts shots fired, whether or not they hit.
• Related的中てきちゅうNeutralA noun for hitting a target, and for predictions or guesses proving right; 「一発」 has no sense of a guess coming true.

Use 「一発」 for one shot or getting something done in one go, as in 「一発で合格」「一発逆転」. Pick 「一撃」 for a single blow or attack, 「ヒット」 for a baseball hit or a hit work, 「命中」 for a bullet striking the mark, and 「的中」 for a prediction coming true.

Usage comparisons are AI-assisted and cross-checked by multiple models; for study reference only

1. 一回いちかいの発射はっしゃや射撃しゃげき。
2. 一回いちかい。
3. 一いち本ぽんのホームラン。