Of the day Definition 1 of 3Pro Tip 1/3Trending Topics Refers to something gaining sudden popularity or relevance, often used on social media. The hashtag of the day is #NationalPuppyDay. Pro Tip 2/3Educational Tool Used by teachers or apps to focus on a specific concept or vocabulary each day. Our idiom of the day is 'barking up the wrong tree'. Pro Tip 3/3Daily Inspiration Used to motivate or provoke thought with a new, meaningful item every day. The motivational quote of the day is about perseverance.