IPA: /ˌoʊvərfəˈmɪljəˌrɪti/
KK: /oʊvərfəmɪljərɪti/
The condition of knowing someone or something too well, often leading to a lack of respect or boundaries.
His overfamiliarity with the new colleagues made them uncomfortable during meetings.
Overfamiliarity → It is formed from "over-" (meaning excessively) and "familiar" (from Latin "familiaris", meaning of a household or intimate) and the suffix "-ity" (meaning the state or condition of). The word describes the state of being excessively familiar or intimate with someone or something.
Think of being 'excessively' ('over-') 'intimate' ('familiar') with someone, which helps you remember that 'overfamiliarity' means being too familiar.