Origin and Etymology of intromission
French, from Middle French, from Medieval Latin intromission-, intromissio, from Latin intromittere
First Known Use: 1601
Medical Definition of intromission
: the insertion or period of insertion of the penis in the vagina in copulation
Seen and Heard
What made you want to look up intromission? Please tell us where you read or heard it (including the quote, if possible).