It is known as different things in differnt parts of the world:
Hen Party
A widow is female and a bachelor is male, so they are the opposite gender. A widow is not the female equivalent of a bachelor. It is the female equivalent of a widower. A spinster is the female equivalent of a bachelor.
In Chinese, we call a female bachelor as "Sheng Nv". Huh
Spinster means an unmarried female
The gender of a bachelor is male while a bachelorette is a female.
Bachelorette
The informal term for a female bachelor is bachelorette.(An earlier term was "spinster" which is seldom used today.)
* Both the male and female are called 'divorcees.'
Spinster
The Bachelor is a television program about finding a mate for the person.
spinster (female) or bachelor (male)
Bachelor
Someone with a bachelor's degree is typically called a graduate.