jednostrzałowiec

[Eng. ‘a single shot’]

1. A tiny person with a slight build, weak, easy to defeat with a single “shot” – punch.
The word was noted in youth slang as early as 2006 (see Miejski.pl) and is still in use today. It has a pejorative connotation.

2. A colloquial synonym for a single-shot weapon in games such as Fortnite.

Examples of usage:
[own translation:]

1. A ‘jednostrzałowiec’ from the first grade came in and started talking about something /overheard; from a 17-year-old talking to his parents about an incident at school?/
2. When a ‘jednostrzałowiec’ starts practising karate or MMA, he becomes a quarter-shot /https://www.cda.pl/video/1638665c/
3. Single-shot – one of the game modes available in Fortnite Battle Royale.
/https://www.google.com/search?q=jednostrza%C5%82owiec&client=firefox-b-d&sxsrf=AJOqlzUuwvvoJOLTN3L6rplqOxLxUv8vKQ:1679649379296&ei=Y2odZIHgEeKyrgSV8Jog&