2) (more commonly) an adjective meaning that someone is very assertive in the pursuit of something and/or hostile to authoritarian manoeuvres by others. A bolshy person gets cross if confronted and is likely to say "what's it to you?", "mind your own business" and stuff like that a lot.
3) also the name of a short-lived youth magazine run by the Alliance for Workers' Liberty.
A lot of students get a bit bolshy after a few pints.
Of late I have been witness to a friend finding himself getting more and more frustrated by south african women. Both dating and freindships he keeps getting the thin end of the wedge. We live in the middle east and his terminology to sum this particular species was "bolshy".