noun, noun or participle which takes 'suru', intransitive verb, noun which may take the genitive case particle 'no'
big craze; boom; huge popularity
Refers to something becoming explosively popular, such as a product, fashion, or trend. Often used with する to mean 'become a big hit'.
このゲームは今、大流行りしている。
This game is a huge craze right now.
大流行りのスイーツ
I went to buy the hugely popular sweets.
noun, noun or participle which takes 'suru', intransitive verb, noun which may take the genitive case particle 'no'
widespread contagion; large outbreak
Used for infectious diseases spreading widely. Less common than the trend sense; often replaced by 大流行 (だいりゅうこう) in formal contexts.
インフルエンザが大流行りして、学校が休校になった。
Influenza spread widely and schools were closed.