noun
frequency; popularity; currency
Refers to how often something occurs or how widely it is accepted, often used in formal or statistical contexts.
この言葉の盛行は近年高まっている。
The frequency of this word has been increasing in recent years.
noun or participle which takes 'suru'
perform well; be successful
Describes something (often an event, plan, or activity) going well or being successful; used with する.
新企画が盛行するかどうかはまだわからない。
We still don't know whether the new project will be successful.