As noted by others, a slang term for buddy.
However, for those
interested, I would highlight that this term enjoys special status in the
Canadian military, and you should be cautious how you use it if new to the Forces.
While "Budz" may be used as a greeting, in the CF it also often carries slightly pejorative connotations, and is generally used in a
condescending context. Thus, do not "budz" anyone unless it's deserved. Accordingly, you should never "budz up" - ie, use the term towards a superior - but only ever "budz down" (ie, "budz" someone of lower rank).
See below for examples.
As a greeting: (Warrant Officer to a Private) "How's it goin' budz?"
As an insult: (Warrant Officer to a Private) "Holy fuck budz, why are you asleep when you should be covering your arcs?"
As a
guaranteed way to
get yourself into shit: (Private to Warrant Officer) "
How's it going, budz? ... I mean, Warrant?"