'antechoir' originates from French, specifically the word 'antechoeur', where 'ante-' meant 'before' and 'choeur' meant 'choir'.

'antechoir' changed from the Old/Middle French word 'antechoeur' and was adopted into English with the form 'antechoir'.

Initially, it meant 'the space before the choir in a church', and over time this specific architectural meaning has been retained in English.