Another addition to the "dere" family of characters in the Japanese entertainment industry/otaku subculture. "Uso" means to "
lie", so when combined with "dere", it would mean that a person being categorised as an "usodere" would be a compulsive
liar.
This term first appeared in Japanese eroge "Usodere!" released by Nounai Kanojo on 18th
December 2009.