Being extremely interested or greatly curious about something; showing keen interest.
子どもたちは昆虫の観察に興味津々だった。
The children were full of curiosity while observing the insects.
新しいゲームの話を聞くと、彼はいつも興味津々になる。
When he hears about a new game, he always becomes very interested.
展示品を前にして来場者は興味津々の表情を浮かべていた。
In front of the exhibits, the visitors wore expressions of eager interest.