Final answer:
The separation of the nail from the nail bed is known as onycholysis, where the nail plate detaches from the nail bed.
Step-by-step explanation:
The term that means separation of the nail from the nail bed is onycholysis. This condition occurs when the nail plate becomes detached from the underlying nail bed, leading to a potentially painful and aesthetically troubling ailment. The nail plate (or body) is the hard, protective part that is visible on the tips of fingers and toes, and separation can occur due to various reasons including trauma, infection, or systemic diseases.