boilyoudaoicibaDictYouDict
boil: Boil ‘large spot’ [OE] and boil ‘vaporize with heat’ [13] are distinct words. The former comes from Old English byl or byle, which became bile in Middle English; the change to boil started in the 15th century, perhaps from association with the verb. The Old English word goes back ultimately to a West Germanic *būlja, whose central meaning element was ‘swelling’; from it also comes German beule ‘lump, boil’.

The verb’s source, via Anglo-Norman boiller, is Latin bullīre, a derivative of bulla ‘bubble’, a word which also gave us bull (as in ‘Papal bull’), bullion, bowl (as in the game of ‘bowls’), budge, bullet, bulletin and bully (as in ‘bully beef’), as well, perhaps, as bill.
=> bill, bowl, budge, bull, bullet, bulletin, bullion, bully, ebullient
bowlyoudaoicibaDictYouDict
bowl: Bowl ‘round receptacle’ [OE] and bowl ‘ball used in bowls’ [15] come from different sources. The former (Old English bolle or bolla) comes ultimately from the Germanic base *bul-, *bal-, which was also the source of English ball, balloon, and ballot. The Middle Dutch form corresponding to Old English bolle was bolle, which was borrowed into English in the 13th century as boll, initially meaning ‘bubble’ but latterly ‘round seed-head’.

The other bowl was originally simply a synonym for ball, but its modern specialized uses in the game of bowls, and the verbal usage ‘deliver the ball’ in cricket and other games, had already begun their development in the 15th century. The word came via Old French boule from Latin bulla ‘bubble’, which also lies behind English boil, bull (as in ‘papal bull’), bullion, bullet, bulletin, and bully (as in ‘bully beef’), as well, perhaps, as bill.
=> ball, balloon, ballot; boil, bull, bullet, bulletin, bully
bullyyoudaoicibaDictYouDict
bully: [16] Bullies have undergone a sad decline in status. In the 16th century the word meant ‘sweetheart’: ‘Though she be somewhat old, it is my own sweet bully’, John Bale, Three laws 1538. But gradually the rot set in, its meaning passing through ‘fine fellow’ to ‘blusterer’ to the present-day harasser of inferiors. In the 18th and 19th centuries it also meant ‘pimp’.

It is probably a modification of Dutch boele ‘lover’ which, as a term of endearment, may have originated as baby-talk. This bully has no connection with the bully of bully beef [18], which comes from French bouilli, the past participle of bouillir ‘boil’. The bully of bully off [19], a now discontinued way of starting play in hockey, appears to come from a term for ‘scrummage’ in Eton football, but whether that is related to the cruel bully is not clear.