Carnal knowledge and Sexual relations

Carnal knowledge noun - The act of sexual procreation between a man and a woman; the man's penis is inserted into the woman's vagina and excited until orgasm and ejaculation occur.

Sexual relations and carnal knowledge are semantically related In some cases you can use "Sexual relations" instead a noun phrase "Carnal knowledge".

Sexual relations noun - Sexual union involving penetration of the vagina by the penis.

Carnal knowledge and sexual relations are semantically related in having sex topic. You can use "Carnal knowledge" instead a noun phrase "Sexual relations".