The study of sexuality, including sexual cultures, sexual orientations, etc.

Coitus or genital-genital sexual contact. / Sexual interaction, usually involving vaginal and/or anal and/or oral penetration, between at least two organisms.

Sexual orientation.

One's tendencies of sexual attraction, considered as a whole.

(psychology) A psychological complex involving fixations of a sexual nature; a fetish.

Harassment in the form of unwelcome sexual advances.

Any act involving sexual stimulation; a sex act.

Any kind of sexual relations between two or more individuals.

(idiomatic) Libidinal unrest arising between individuals when exposed to one another.

(idiomatic) Behaviour of a sexual nature between one or more individuals.