What does "blister" mean?

Additional senses

1. 2.A vesicatory; a plaster of Spanish flies, or other matter, applied to raise a blister. Dunglison. Blister beetle, a beetle used to raise blisters, esp. the Lytta (or Cantharis) vesicatoria, called Cantharis or Spanish fly by druggists. See Cantharis. -- Blister fly, a blister beetle. -- Blister plaster, a plaster designed to raise a blister; -- usually made of Spanish flies. -- Blister steel, crude steel formed from wrought iron by cementation; -- so called because of its blistered surface. Called also blistered steel. -- Blood blister. See under Blood.
2. 3.To be affected with a blister or blisters; to have a blister form on. Let my tongue blister. Shak.
3. 4.To raise a blister or blisters upon. My hands were blistered. Franklin.
4. 5.To give pain to, or to injure, as if by a blister. This tyrant, whose sole name blisters our tongue. Shak.