Synonyms for Bolshy (same or very similar meaning)
WordNet sense 1 (emotionally charged terms used to refer to extreme radicals or revolutionaries):
bolshevik, red, Marxist, bolshieWordNet sense 2 (obstreperous):
stroppyWordNet sense 3 (tenaciously unwilling or marked by tenacious unwillingness to yield):
obstinate, stubborn, unregenerateFrom the ODE community, based on WordNetadd/edit