1. A strong, aggressively protective mother. Likened to literal mother bears, which are notoriously violent and aggressive when confronting a danger to their offspring. She's usually quite demure and reserved, but she turns into a straight-up lady bear if you so much as look at her kids the wrong way.

2. dated A female police officer. The two fellas were busting each other up when a lady bear on patrol came round and threw them both in her squad car.