absolutely required and not to be used up or sacrificed
absolutely necessary; vitally necessary; "essential tools and materials"; "funds essential to the completion of the project"; "an indispensable worker"
being or relating to or containing the essence of a plant etc; "essential oil"
the lower part of the female reproductive tract; a moist canal in female mammals extending from the labia minora to the uterus; "the vagina receives the penis during coitus"; "the vagina is elastic enough to allow the passage of a fetus"