This is the 4278th most frequent Russian word.
актив
"Актив" in English means "asset" or "active members" depending on the context.
актив refers to 'assets' in an economic or financial context.
Актив компании значительно вырос за последний год.
The company's assets have grown significantly over the past year.
актив refers to an organized group, like a council or committee.
Школьный актив организовал мероприятие для учеников.
The school council organized an event for students.
актив in this sentence modifies 'participant' and is synonymous to 'active,' although technically not a direct use of the word.