means A thorn is a sharp, stiff, woody point growing on a plant stem, evolved to deter animals from eating or trampling it.

from From Old English 'thorn,' which traveled down from a Proto-Germanic root (compare German 'Dorn' and Dutch 'doorn'), itself reaching back to a Proto-Indo-European root meaning 'to pierce.' The word so embodied sharpness that the early English even named a letter after it: the runic-derived character þ, called 'thorn,' which once stood for the 'th' sound — a prickly little glyph that survives today only in faux-archaic spellings like 'Ye Olde Shoppe,' where that 'Y' is really a misread thorn.