n. (from Russian) A word used as an insult and accusation by the Bolsheviks in the Soviet Union, meaning a wealthy, land-owning peasant, with the connotation of being greedy and acting above one's station. It was used extensively by the Soviets to refer to the anarchist revolutionaries of the Makhnovshchina (Nestor Makhno's army) in Ukraine during the First World War.
"Release the anarchists I'm holding in prison?" replied Lenin with a laugh to Berkman and Goldman. "I have no anarchists in prison, just some worthless counterrevolutionary kulaks."
n. (from Russian) An informer. One who turns in one's friends, family, and neighbours to the secret police, usually for a reward or advantage. It is considered one of the foulest insults in the Russian language.
Anyone who would drop a dime on his friends is a slimy stukach.