When a character's hands or feet float around them as opposed to being physically attached via arms or legs. Rayman is one of the most iconic characters with this trait, hence the tag's name.
The distinct chibi style of the Power Pros series, and a number of Kirby characters (such as Magolor) and Pokémon's Haunter also feature this limb style.
Please note that disembodied hand is for limbs without a body. It does not apply to Rayman limbs.