'baggy' originates from English, specifically the word 'bag' combined with the adjectival suffix '-y' (meaning 'characterized by').

'bag' came into English from Old Norse 'baggi' meaning 'a bundle' or 'pack'; over time English formed the adjective 'baggy' (bag + -y) to mean 'like a bag' or 'loose like a bag', and 'baggiest' is the superlative form of that adjective.

Initially, the root sense referred to something 'like a bag' (i.e., a bundle or sack); over time it evolved to describe clothing that hangs loosely, and now 'baggiest' means 'most loose-fitting'.