intimacy
[ U ] a situation in which you have a close friendship or sexual relationship with someone:
Intimacy between teachers and students is not recommended.
[ C usually plural ] things that are said or done only by people who have a close relationship with each other:
It was obvious from their witty intimacies that they had been good friends for many years.
intimacy
Cambridge English Dictionary
https://dictionary.cambridge.org/dictionary/english/intimacy
[ U ] a situation in which you have a close friendship or sexual relationship with someone:
[ C usually plural ] things that are said or done only by people who have a close relationship with each other:
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[C] Countable noun: a noun that has a plural.
[U] Uncountable or singular noun: a noun that has no plural.
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Thesaurus: synonyms and related words
Friendly
affable amiable amicable amity approachable closeness cordial cordiality cordially familiarity family-friendly Freemasonry harmonious jovial likeable matey neighbourly nice thaw tête-à-tête
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Intimate relationship
Wikipedia
https://en.wikipedia.org/wiki/Intimate_relationship
An intimate relationship is an interpersonal relationship that involves physical or emotional intimacy. Physical intimacy is characterized by friendship, platonic love, romantic love, or sexual activity. While the term intimate relationship commonly implies the inclusion of a sexual relationship, the term is also used as a euphemism for a relationship that is strictly sexual.
Intimate relationships play a central role in the overall human experience. Humans have a general desire to belong and to love, which is usually satisfied within an intimate relationship. These relationships involve feelings of liking or loving one or more people, romance, physical or sexual attraction, sexual relationships, or emotional and personal support between the members. Intimate relationships allow a social network for people to form strong emotional attachments.