familiarity

noun

1 he wants to gain greater familiarity with European politics:

acquaintance with, acquaintanceship with, awareness of, experience of, insight into, conversancy with, conversance with;

knowledge of, understanding of, comprehension of, cognizance of, grasp of, mastery of, skill with, skill in, proficiency in, expertise in.

2 the reassuring familiarity of his parents' home:

ordinariness, customariness, normality, conventionality.

3 they feel comfortable with you because of your familiarity:

informality, casualness, ease, comfortableness, friendliness, lack of ceremony, lack of restraint, lack of reserve, naturalness, simplicity.

4 she was affronted by his familiarity:

overfamiliarity, presumption, presumptuousness, forwardness, boldness, audacity, cheek, impudence, impertinence, intrusiveness, disrespect, disrespectfulness;

liberties;

informal sauce, cockiness;

archaic assumption.

5 our familiarity allows us to give each other nicknames:

closeness, intimacy, attachment, affinity, friendliness, friendship, amity;

informal chumminess, palliness;

British, informal mateyness.

familiarity Oxford Dictionary of English