intercourse
n. uncountablen. the act of having sex. It can also mean the exchange of ideas or feelings between people, though this is less common today.
n. physical sexual contact between individuals, typically involving penetration. In a broader social context, refers to the exchange of thoughts, feelings, or communication between people.
The doctor discussed the risks of unprotected intercourse.
Social intercourse between the two neighboring tribes was limited to trading goods at the border once a month.
While the term is most frequently used in a biological sense today, older literature often uses it to describe the intellectual intercourse that occurs within a vibrant academic community.
Various theories; see Wikipedia article.
Uncountable in both its sexual and social senses; the social sense is increasingly formal or literary.