"Enthusiastic interest" refers to being extremely interested and passionate about something. It means feeling excited and eager to learn, explore, or engage in a particular topic or activity. Full definition
If the dog does not show enthusiastic interest in the food, then this is not the right time to begin training. (perfectpaws.com)
«That's nice, dear» is not a great way to show enthusiastic interest for your partner and people in healthy relationships know that it takes more effort. (powerofpositivity.com)
But the fact that both Barry and Southside with You separately took enthusiastic interest in young Obama's smoking habits takes it to another level. (decider.com)