boil (n.) Look up boil at
"hard tumor," altered from Middle English bile (Kentish bele), perhaps by association with the verb; from Old English byl, byle "boil, carbuncle," from West Germanic *buljon- "swelling" (source also of Old Frisian bele, Old High German bulia, German Beule). Perhaps ultimately from PIE root *bhel- (2) "to blow, swell," or from *beu- "to grow, swell" (see bull (n.2); also compare boast (n.)). Compare Old Irish bolach "pustule," Gothic ufbauljan "to puff up," Icelandic beyla "hump."
boil (v.) Look up boil at
early 13c. (intransitive) "to bubble up, be in a state of ebullition," especially from heat, from Old French bolir "boil, bubble up, ferment, gush" (12c., Modern French bouillir), from Latin bullire "to bubble, seethe," from PIE *beu- "to swell" (see bull (n.2)). The native word is seethe. Figurative sense, of passions, feelings, etc., "be in an agitated state" is from 1640s.
I am impatient, and my blood boyls high. [Thomas Otway, "Alcibiades," 1675]
Transitive sense "put into a boiling condition, cause to boil" is from early 14c. The noun is from mid-15c. as "an act of boiling," 1813 as "state of boiling." Related: Boiled; boiling. Boiling point "temperature at which a liquid is converted into vapor" is recorded from 1773.