Intimacy (noun)

1. Close familiarity or friendship; closeness.
2. A close, familiar, and usually affectionate or loving personal relationship with someone.
3. A private or secret matter or relationship.
4. The state or quality of being intimate; closeness, familiarity.
5. The act of having sexual intercourse.

Origin:

Late 16th century: from french intimité or latin intimitas, from intimus "innermost".

Examples:

1. The couple shared a deep intimacy, built on years of trust and mutual understanding.
2. Their intimacy was such that they could talk about anything, no matter how personal or intimate.
3. The intimacy of their friendship was strengthened by their shared experiences and interests.
4. She kept the details of her relationship with him a secret, not wanting to compromise the intimacy between them.
5. They enjoyed a physical intimacy, exploring each other's bodies with a sense of wonder and discovery.