How to say "terrorism" in Japanese

• テロCommon
  nounA shortened form covering both 'terror' and 'terrorism'; it is at home in news reports and everyday talk about actual attacks, and typically points to concrete incidents rather than terrorism as an idea.
  地球ちきゅう側がわの圧政あっせいに苦くるしむコロニーの人々ひとびとの中なかで、テロによる現状げんじょう打破だはを目論もくろむ勢力せいりょくが誕生たんじょう。↗

  Among the people of the colonies suffering under Earth's tyranny a force emerges intending to overthrow the status quo through terrorism.
• テロリズムCommon
  nounThe full loanword for terrorism; it treats terrorism as a phenomenon or concept, so it fits discussion of its nature, causes, and definition, while the shorter テロ covers most references to actual incidents.
  ９.１１テロ以来いらい、世界せかいの各地かくちで大規模だいきぼなテロリズムが発生はっせいしている。↗

  Since 9.11 large scale acts of terrorism have occurred all over the world.

Both are common loanwords meaning terrorism: use 「テロ」, the shortened form, for terrorism in general and concrete attacks in news and conversation, and 「テロリズム」 when treating terrorism as a phenomenon or concept in fuller discussion.

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

• テロterror
• テロリズムterrorism
• テロルterror
• 恐怖政治きょうふせいじpolitics of fear