'baccy' originates from English, specifically a clipped form of the word 'tobacco' (originally from Spanish 'tabaco').

'baccy' developed as a colloquial/clipped form from 'tobacco' (which passed into English via Spanish 'tabaco' and French 'tabac'), becoming British slang 'baccy' and the plural 'baccies'.

Initially related to the plant and its leaves ('tobacco'), it evolved into informal usage meaning 'tobacco products' or 'cigarettes' (particularly in everyday British speech).