Merriam-Webster's Collegiate® Dictionary, 11th Edition
FAMILIAR
I. noun
Date: 13th century
a member of the household of a high official, one that is familiar, a spirit often embodied in an animal and held to attend and serve or guard a person,
4. one who is well acquainted with something, one who frequents a place,
II. adjective
Etymology: Middle English familier, from Anglo-French, from Latin familiaris, from familia
Date: 14th century
closely acquainted ; intimate , affable , sociable ,
3. of or relating to a family , frequented by families ,
4. being free and easy , marked by informality , overly free and unrestrained ; presumptuous , moderately tame ,
5. frequently seen or experienced ; easily recognized , of everyday occurrence , possibly known but imperfectly remembered , having personal or intimate knowledge, see: common familiarly adverb familiarness noun