An adjective used to express sadness, annoyance, dissapiontment or mild anger. Sadface as well as Angryface, Happyface etc. can be/is used to replace an emoticon
*sadface replaces >:(*
Any emotion followed by -face can be used to decribe how you're feeling.
*I accidentally killed my pet fish. sadface.
*What!? I got an F on my english test! sadface!
*Sooo, my girlfriend is definitely fucking my bestfriend. sadface.