blister
n.
c.1300, perhaps via Old French blestre "blister, lump, bump," from a Scandinavian source (compare Old Norse blastr "a blowing," dative blæstri "swelling"), or from Middle Dutch blyster "swelling;" perhaps from PIE *bhlei- "to blow, swell," extension of root *bhel- (2) "to blow, inflate, swell;" see bole.
v.
"to become covered in blisters," late 15c.; "to raise blisters on," 1540s, from blister, n.. Related: Blistered; blistering.