From the latin
pluri -many and
potente(?) - power (mea culpa, Latin was long ago for me:). Basically means can change into anything, so a
shapeshifter would be pluirpotent if it could assume any form.
More usually, it refers to cells (like embryonic cells) that can differentiate into many different cell types (muscle, bone, skin, hair etc). This is not usually relevant for somatic tissue which should remain what it started out as. However, pluripotent != totipotent - that is, pluripotent cells are more limited than totipotent ones.
Some organisms, like carrots, apparently have all pluripotent tissue, so you should be able to regrow the whole thing from a fragment (I haven't tried).