1. To bend or incline closer to the interior or central point of something, such as a structure, classroom, group of people, etc. I had to lean in to hear what the professor was saying. We all leaned in to look at the specimen in the tank. Water damage has caused the wall in our living room to start leaning in.

2. A phrase used to encourage professional women to pursue career advancement and leadership roles. It comes from the title of Sheryl Sandberg's 2013 book Lean In: Women, Work, and the Will to Lead, about her career and role as a Facebook executive. In the spirit of leaning in, I'm going for that big promotion at work. Sure, the idea of leaning in and taking on more responsibility at the office is nice and all, but it's simply unfeasible for a single mother of three like myself.