'peer' originates from Old French 'pair', ultimately from Latin 'par', where 'par' meant 'equal'.

'peer' changed from Old French 'pair' (meaning 'equal one') into Middle English forms (e.g. 'pere', 'peer') and eventually became the modern English word 'peer'.

Initially, it meant 'an equal' (one of equal standing); over time this developed into the modern senses of 'a person of equal status' and the specific sense 'a member of the nobility' as well as the verb sense 'to look closely'.