Pronunciation: (fu-mil"ē-ar'i-tē, -mil-yar'-),[key] —n., —pl.-ties. 1. thorough knowledge or mastery of a thing, subject, etc.
2. the state of being familiar; friendly relationship; close acquaintance; intimacy.
3. an absence of ceremony and formality; informality.
4. freedom of behavior justified only by the closest relationship; undue intimacy.
5. Often, familiarities. an instance of such freedom, as in action or speech.
6. a sexual liberty or impropriety.