火星人(かせいじん)

かせいじん
noun
Martian; inhabitant of Mars
person
1. Martian; inhabitant of Mars
A fictional or hypothetical being from the planet Mars. Used in science fiction and popular culture, and sometimes figuratively to describe someone who seems completely out of touch or alien.
その映画(えいが)には火星人(かせいじん)が登場(とうじょう)する。
Martians appear in that movie.
子(こ)どもの頃(ころ)、火星人(かせいじん)は本当(ほんとう)にいると信(しん)じていた。
When I was a child, I believed Martians really existed.
あの人(ひと)の考(かんが)え方(かた)はまるで火星人(かせいじん)みたいで、誰(だれ)も理解(りかい)できない。
That person's way of thinking is like a Martian's — nobody can understand it.

Composed of 火星(かせい) (Mars, the planet) and 人(じん) (person). Follows the productive pattern of planet name + 人(じん) to form hypothetical alien inhabitants: 金星人(きんせいじん) (Venusian), 木星人(もくせいじん) (Jovian), etc.

Common collocations

Cultural note

The concept of 火星人(かせいじん) became widespread through H.G. Wells' "The War of the Worlds" (1898), which was translated into Japanese. The classic image of a Martian with a large head and tentacles (タコ型(がた)火星人(かせいじん), "octopus-type Martian") remains a staple of Japanese pop culture and manga.

Related words

  • 宇宙人(うちゅうじん): alien; extraterrestrial — the general term for any being from space
  • 地球外生命体(ちきゅうがいせいめいたい): extraterrestrial life — formal/scientific
general
Added 2026.5.4 21:47 · Revised 2026.9.2 13:02
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