How to say "intruder" in Japanese

• 侵入者しんにゅうしゃ
  nounThe broadest of these words: anyone who enters a place, building, or territory without permission, whether a trespasser, an invader, or a raider. The word to reach for when no special nuance is intended.
  ビルは侵入者しんにゅうしゃによって殺ころされた。↗

  Bill was killed by an intruder.
• 闖入者ちんにゅうしゃ
  nounAn intruder who forces or bursts their way in uninvited, stressing sudden, forcible entry rather than stealth; fits a trespasser who pushes into a home, office, or restricted area.
• 乱入者らんにゅうしゃ
  nounSuggests someone who barges or storms in wildly, disrupting what is going on; it is uncommon, so it is seldom the word you want for an ordinary intruder.
• 潜入者せんにゅうしゃ
  nounCovers the stealthy sense of 'intruder': someone who sneaks into a place or organization covertly, an infiltrator rather than an open trespasser; use it when secrecy is the point.

All four denote someone who enters uninvited: 侵入者 is the broadest (trespasser, invader, raider); 闖入者 implies forcing or bursting in, 潜入者 sneaking in covertly, and 乱入者 barging in disruptively.

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

• 侵入者しんにゅうしゃintruder
• 闖入者ちんにゅうしゃintruder
• 乱入者らんにゅうしゃintruder
• 潜入者せんにゅうしゃintruder