An adult who has not had enough sex, commensurate with his/her age.
Undersexed individuals find themselves in a vicious circle. Because they lack the sexual experience, they are not confident about sex and hence they rarely get any.
Many serial killers were undersexed. Harvard students are undersexed. Hence, Harvard students are serial killers
A hardo is a person who tries extremely hard at everything. Most times a hardo will try very hard at things that do not require excessive effort. For example, sports practices, gym class, etc.
Wow did you see Jack at practice today? What a hardo!