'firedog' originates from English, specifically the compound of the words 'fire' and 'dog', where 'fire' meant 'combustion, hearth' and 'dog' was used figuratively for a projecting piece of iron or support.

'firedog' changed from the Middle English compound 'fire-dog' (a combination of 'fire' + 'dog') and eventually became the modern English word 'firedog'.

Initially, it referred to a 'dog' or metal prop used at the fire; over time it retained the specialized meaning of a metal support for holding logs in a fireplace.