Bud \bud\ as a boy's name is pronounced bud. It is of English origin, and the meaning of Bud is "brother". Nickname used since medieval times, and modern slang and short form for "buddy" or "brother". It can also refer to a sprouting plant or a young boy. Also possibly from Scotish Gaelic "a bhodaich", meaning "old man". Actor Buddy Ebsen; comedians Bud Abbott, and Buddy Hackett.
For more information, see also the related name Buxton.