Stands for “that is exceedingly humorous”
A slang for posh english people
Susan: take a glance at this *shows meme*
You: that is exceedingly humorous, Susan.
tieh
Means "yeah man" or rarely, "yes madam"
Slang in the UK
Madam Susan: Shall we go for some tea, Claryce?
Servant Claryce: Oh, ym.
Gangster Thomas: Ayo mah man, Caitlin, how's it in thugcademy?? Tis' goooood?
Pre-thug Caitlin: ym!!