It is a slang used by Hungarian speakers. Originates from the word "Bátty" which means "brother (male)". It is mainly used in rural areas and in some districts of Budapest (Mainly district 8 and 9 and some of the 10s). The slang was started by gypsies, its a friendly way of invocation between males, but is often used with females as well.
by WaifuRacer August 1, 2018