Merriam-Webster's Collegiate® Dictionary, 11th Edition
PEER
I. noun
Etymology: Middle English, from Anglo-French per, from per, adjective , equal, from Latin par
Date: 13th century
one that is of equal standing with another ; equal , companion ,
3. a member of one of the five ranks (as duke, marquess, earl, viscount, or baron) of the British peerage, noble 1, peer adjective
II. transitive verb
Date: 14th century
rival , match ,
III. intransitive verb
Etymology: perhaps by shortening & alteration from appear
Date: 1580
to look narrowly or curiously, to come slightly into view ; emerge partly