'preoperculum' originates from New Latin and ultimately from Latin, specifically formed from the prefix 'pre-' and the Latin word 'operculum', where 'pre-' meant 'before' and 'operculum' meant 'little lid'.

'preoperculum' was created in New Latin by prefixing Latin 'operculum' with 'pre-' and was later borrowed into scientific English as the anatomical term 'preoperculum'.

Initially it literally meant 'before the little lid'; over time, in anatomical usage it came to denote the specific bony element located in front of the operculum (gill cover) in fishes.