What does "itch" mean?

Additional senses

1. 2.(Med.) An eruption of small, isolated, acuminated vesicles, produced by the entrance of a parasitic mite (the Sarcoptes scabei), and attended with itching. It is transmissible by contact.
2. 3.Any itching eruption.
3. 4.A sensation in the skin occasioned (or resembling that occasioned) by the itch eruption; -- called also scabies, psora, etc.
4. 5.A constant irritating desire. An itch of being thought a divine king. Dryden. Baker's itch. See under Baker. -- Barber's itch, sycosis. -- Bricklayer's itch, an eczema of the hands attended with much itching, occurring among bricklayers. -- Grocer's itch, an itching eruption, being a variety of eczema, produced by the sugar mite (Tyrogluphus sacchari). -- Itch insect (Zoöl.), a small parasitic mite (Sarcoptes scabei) which burrows and breeds beneath the human skin, thus causing the disease known as the itch. See Illust. in Append. -- Itch mite. (Zoöl.) Same as Itch insect, above. Also, other similar mites affecting the lower animals, as the horse and ox. -- Sugar baker's itch, a variety of eczema, due to the action of sugar upon the skin. -- Washerwoman's itch, eczema of the hands and arms, occurring among washerwomen.