A quirky, silly and/or stupid, socially inept person, or one who is out of touch with contemporary trends. Often confused with nerd and geek, but does not imply the same level of intelligence.
A penis.
saddo
noun
A pathetic or socially inept person; a nerd.
How often have the words dork and saddo occurred in a corpus of books? (source: Google Ngram Viewer )