intimacy {in-tuh-muh-see} -noun, plural -cies 1. the state of being intimate 2. a close, familiar, and usually affectionate or loving personal relationship with another person or group. 3. a close association with or detailed knowledge or deep understanding of a place, subject, period of history, etc. 4. an act or expression serving as a token of familiarity, affection, or the like. 5. an amourously familiar act; liberty 6. sexual intercourse 7. the quality of being comfortable, warm, or familiar: the intimacy of a room. 8. privacy, esp. as suitable to the telling of a secret.