'pro-bishop' originates from English, combining the prefix 'pro-' (from Latin 'pro', meaning 'for') and the word 'bishop' (from Old English 'bisceop', ultimately from Greek 'episkopos' meaning 'overseer').

'bishop' changed from Old English 'bisceop' (in Medieval English and Latin from 'episcopus') and eventually became the modern English word 'bishop'; the compound 'pro-bishop' is a straightforward combination of 'pro-' + 'bishop' formed in Modern English.

Initially formed simply to mean 'for the bishop' (literally 'in favor of a bishop'); over time it has been used descriptively as an adjective and nominally as someone who supports bishops, with the core sense of support remaining.