Synonyms for boil

verb

1. To subject to or continue boiling

   seethe, simmer, bubble, stew, steam, parboil, blanch, poach, coddle, scald, heat, brew, steep, boil over, evaporate, sterilize, autoclave; see also cook.

2. To seethe

   effervesce, gurgle, percolate, seethe, churn, froth, foam, ferment, surge, tumble, burble; see also bubble.

3. To be angry

   fume, seethe, sputter, quiver with rage; see fume, rage 1.

boil, the basic word, refers to the bubbling up and vaporization of a liquid over direct heat or, metaphorically, to great agitation, as with rage it made my blood boil; seethe suggests violent boiling with much bubbling and foaming or, in an extended sense, excitement the country seethed with rebellion; simmer implies a gentle, continuous cooking at or just below the boiling point or, metaphorically, imminence of eruption, as in anger or revolt; stew refers to slow, prolonged boiling or, in an extended colloquial sense, unrest caused by worry, anxiety, or resentment