How to say "diffuse" in Japanese

• 行き渡るいきわたるCommon
  godan verb, intransitive verbCovers the verb sense of 'diffuse': something spreads until it reaches every part of an area, organization, or group, with a nuance of thorough permeation, like news or a custom becoming widespread.
  この雑誌ざっしは広ひろく行いき渡わたっている。↗

  This magazine circulates widely.
• 散漫さんまんCommon
  na-adjective, nounCovers 'diffuse' as an adjective meaning unfocused or rambling: it describes writing, speech, or attention that lacks concentration and wanders, rather than anything physically spreading.
  寝不足ねぶそくだと注意ちゅういが散漫さんまんになりがちです。↗

  When you lack sleep, you are apt to be careless.

Use 「行き渡る」 for the verb sense of diffusing, when something spreads until it reaches every part of an area or group, and 散漫 for the adjective sense describing unfocused, rambling writing or speech.

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

• 行き渡るいきわたるto diffuse
• 散漫さんまんvague
• びまん性びまんせいdiffuse