fa·mil·iar

[fuhmil-yer] 

adjective

1.  Commonly or generally known or seen: a familiar sight.
2.  Well-acquainted; thoroughly conversant: to be familiar with a subject.
3.  Informal; easygoing; unceremonious; unconstrained: to write in a familiar style.
4.  Closely intimate or personal: a familiar friend; to be on familiar terms.
5.  Unduly intimate; too personal; taking liberties; presuming: The duchess disliked familiar servants.