IPA: /rɪˈpʌlsər/
KK: /rɪˈpʌlsər/
A person or thing that drives back or repels something.
The repulser was effective in keeping the intruders away from the area.
Repulser → It is formed from "re-" (meaning back or again) and "pulsare" (meaning to push or drive). The word "repulser" refers to someone or something that pushes back or drives away.
Think of 'pushing back' ('re-' means back and 'pulsare' means to push) — that's why a repulser is something that drives away.