1. Literally, to kneel down, usually in a show of respect, fealty, awe, subjection, or reverence. The members of the congregation all fell to their knees to begin their morning prayer. I fell to my knees at the sight of the devastation.

2. By extension, any extravagant or elaborate display or expression of praise, adoration, respect, or reverence. Many believe that the company's newest product will make converts of many and cause current fans to fall to their knees in admiration.