Webster's Revised Unabridged Dictionary · 1913

Teasel

Teasel , noun

[Old English tesel, Anglo-Saxon tasel, tasl, the fuller's herb. See Tease.]

1.
(Botany) A plant of the genus Dipsacus, of which one species (Dipsacus fullonum) bears a large flower head covered with stiff, prickly, hooked bracts. This flower head, when dried, is used for raising a nap on woolen cloth.

Small teasel is Dipsacus pilosus, wild teasel is Dipsacus sylvestris.

2.
A bur of this plant.
3.
Any contrivance intended as a substitute for teasels in dressing cloth.
Collocations (1)
Teasel frame , a frame or set of iron bars in which teasel heads are fixed for raising the nap on woolen cloth.

Teasel , transitive verb

To subject, as woolen cloth, to the action of teasels, or any substitute for them which has an effect to raise a nap.