"Fembot" is the term used to describe a female robot. It is thus the opposite of "manbot", which describes a male robot.
According to Professor Hubert J. Farnsworth, the differences between the two robot sexes are "ill defined". The main difference between them being their type of oil, and apparent design of the robots to emulate the human sexes. For man robots, the interior of a fembot would be the same of a nude human woman for a human man (though it could be the same for man robots).