"Keep it 100 on the land" means to stay completely real, honest, and authentic in all situations, grounded and true to yourself and others. The phrase "keep it 100" or "keep it one hundred" is slang for being genuine or truthful without any pretense. In the context of the phrase "keep it 100 on the land," it emphasizes maintaining that honesty and authenticity especially while being grounded or "on the land," symbolizing solid, real-life circumstances. This phrase has been popularized and interpreted in various ways, including in recent Taylor Swift lyrics where it means pledging loyalty and staying true in all aspects—on land, sea, and sky—reflecting commitment and realness in all environments and conditions.