Other forms: buddies
A buddy is a close friend, said informally. My old buddy, buddies from school, a buddy system.
It is chiefly American and warm. A buddy system pairs people so each looks after the other — in diving it is a genuine safety rule and in schools it is a way of settling new pupils. As a form of address to a stranger, buddy can be friendly or distinctly not, depending entirely on tone. Note buddy up; and that the word's origin is uncertain, possibly a child's version of brother.
1nounbuddyA close friend, said informally.
“I'm going fishing with my old school buddy this weekend.”
buddy is a friend.
The word appears about 1788 with no certain origin — possibly a child-talk form of brother, possibly from the British dialect butty, a companion.
Scots
buddo
English, today
buddy
Built from
First appears c. 1788, in the writings of Charles Dibdin, of unknown origin. Possibly from bruddy, bruthy, a child-talk alteration of brother. Alternatively, perhaps from British colloquial butty (“companion”), also the form of an older dialect term meaning workmate, associated with coal mining. Itself believed derived from 1530 as booty fellow, a partner with whom one shares booty or loot. Alternatively, compare Scots buddo, bodda (“buddy, kiddo, dear”), related to Icelandic budda* (“purse"; also "short, stout person”).
Etymology from Wiktionary, CC BY-SA