Thorn

A hard and sharp-pointed projection from a woody stem; usually, a branch so transformed; a spine.

Any shrub or small tree which bears thorns; especially, any species of the genus Crataegus, as the hawthorn, whitethorn, cockspur thorn.

Fig.: That which pricks or annoys as a thorn; anything troublesome; trouble; care.

The name of the Anglo-Saxon letter /, capital form /. It was used to represent both of the sounds of English th, as in thin, then. So called because it was the initial letter of thorn, a spine.

To prick, as with a thorn.

a small sharp-pointed tip resembling a spike on a stem or leaf