Sexual relation and Unlawful carnal knowledge

Sexual relation 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.

Unlawful carnal knowledge and sexual relation are semantically related. In some cases you can replace phrase "Unlawful carnal knowledge" with "Sexual relation", this phrases are similar.

Unlawful carnal knowledge noun - Forbidden or tabu sexual intercourse between individuals.

Sexual relation and unlawful carnal knowledge are semantically related. You can use "Sexual relation" instead a noun phrase "Unlawful carnal knowledge".