Lively; active; vigorous — describes people, activities, or discussions that are energetic and animated.
子どもたちは運動会でとても活発に動いていた。
The children were moving very actively at the sports day.
会議では活発な意見交換が行われた。
There was an animated exchange of opinions at the meeting.
彼女は性格が活発で、初対面でもよく話しかけてくる。
She has a lively personality and often speaks to people even on first meeting.
株式市場は最近取引が活発だ。
The stock market has been active in trading recently.