A user friendly slang term used to describe a lady's vagina. That comes from the word Vagina itself but has a differant spelling as not to confuse it with the female name Gina. Used instead of other terms such as fanny, kebab, minge and cunt which can be seen as an inappropriate way of describing the female form. The word is used mainly as an insult.
''Shut it you gyna''
''Did you get near her gyna?''