A prehensile tail, foot, or lip can curl around something and hold on, almost like a hand. Monkeys with prehensile tails hang from branches; a seahorse wraps its tail around seaweed; an elephant’s trunk is often called prehensile because it can grab. It is a biology and nature-documentary word, not everyday chat. You would not usually call a human hand prehensile, even though a hand can grasp — the adjective is saved for body parts that are not hands, but still hold. Though actually, the Latin inside it is simply “able to seize.” That is why it feels scientific: it names a trick of the body, not a personality, and not anything “pre-historic.” Some animals have fully prehensile tails; others have tails that only help a little. If a textbook calls a tail prehensile, it means that tail can take hold, not merely swing.

能纏繞抓握的（尾巴、腳等，像多一隻手）