Sexual activity, especially sexual intercourse, Either of the two divisions, designated female and male, by which most organisms are classified on the basis of their reproductive organs and functions, One of the two divisions of organic beings formed on the distinction of male and female, verb_ stimulate sexually, tell the sex (of young chickens), zoology To determine the biological sex of an animal, transitive verb_ To determine the sex of (an organism), To arouse sexually. Often used with up, To increase the appeal or attractiveness of. Often used with up