デモ

でも
noun
demonstration; protest; demo
1. demonstration; protest march
A public gathering or march to express political or social opposition or support for a cause.
学生(がくせい)たちがデモを(おこな)った。
The students held a demonstration.
反戦(はんせん)デモに何千人(なんぜんにん)もの(ひと)参加(さんか)した。
Thousands of people participated in the anti-war demonstration.
大規模(だいきぼ)なデモ行進(こうしん)道路(どうろ)がふさがれ、(くるま)がまったく(とお)れなくなった。
A large-scale protest march blocked the streets, making it completely impossible for cars to get through.
2. demo; demonstration (of a product or skill)
A practical display or preview showing how something works.
(あたら)しいソフトウェアのデモを()せてもらった。
I was shown a demo of the new software.
このゲームのデモ(ばん)無料(むりょう)でダウンロードできる。
You can download the demo version of this game for free.
デパートの食品売(しょくひんう)()で、有名(ゆうめい)なシェフが料理(りょうり)のデモをしているのを()て、つい(あし)()めてしまった。
I couldn't help stopping when I saw a famous chef doing a cooking demonstration at the department store's food section.

デモ is a shortened form of デモンストレーション (demonstration). Used for both political protests and product/skill demonstrations.

SENSE 1 (PROTEST) COLLOCATIONS:

  • デモを(おこな)う (to hold a demonstration)
  • デモに参加(さんか)する (to participate in a protest)
  • デモ行進(こうしん) (protest march)
  • 反戦(はんせん)デモ (anti-war protest)
  • 抗議(こうぎ)デモ (protest demonstration)
  • 大規模(だいきぼ)なデモ (large-scale demonstration)

SENSE 2 (DEMO/PREVIEW) COLLOCATIONS:

  • デモを()せる (to show a demo)
  • デモ(ばん) (demo version — software/games)
  • デモ() (demo unit/machine)
  • デモ動画(どうが) (demo video)

USAGE:
Context usually makes the meaning clear. In news and political contexts, デモ means protest. In business and tech contexts, it means a demonstration or preview.