'pronaos' originates from Ancient Greek, specifically the word 'pronaós' (προναός), where the prefix 'pro-' meant 'before' and 'naós' meant 'temple' or 'inner chamber.'

'pronaós' in Ancient Greek passed into Latin as 'pronaos' and was borrowed into modern English largely unchanged, keeping its form and architectural sense.

Initially, it meant 'the space before the temple's inner chamber,' and over time it has retained that specialized architectural meaning in modern usage.