IPA: /ˌɪntrəˈmɪʃən/
KK: /ɪntrəˈmɪʃən/
The act of introducing or admitting something, especially in a physical or sexual context.
The intromission is a crucial part of the reproductive process in many species.
Intromission is formed from "intro-" (meaning into) and "mittere" (meaning to send). The word describes the act of sending something into a space or context.
Think of sending something 'into' ('intro-') a place — that's what intromission means.