'platy' originates from Greek, specifically the word 'platys', where 'platys' meant 'broad, flat'.

'platy' came from Ancient Greek 'platys' (πλατύς) and entered New Latin/modern scientific usage as the combining form 'platy-' and later as a common name for certain small aquarium fishes (platyfish).

Initially, it meant 'broad, flat' in Greek; over time it has been retained as a combining form meaning 'flat/broad' and has also become a common name for a group of small freshwater fishes.