This is the 9285th most frequent Japanese word.
発起
"発起" means "initiation" or "the act of starting something, especially a plan or event."
発起人 (hokkinin) here refers to the person who initiates an activity or idea.
彼は住民による街の清掃活動の発起人だ。
He is the initiator of the town's cleaning activity organized by the residents.
発起 (hokki) here refers to the beginning or initiation of a project or idea.
そのプロジェクトの発起は先月だった。
The initiation of that project was last month.
発起 (hokki) in this context means taking initiative or instigating an activity.