The meaning of SMDH is “shaking my damn head”.
It is a slang abbreviation, prevalent on Twitter and Snapchat, used by users to give voice to their disapproval of the shared content or topic.
The abbreviation is a variation of “smh” and in turn it developed from the original one, which is the short form of “shaking my head”.
“Smh” can be traced back to 1994 and like many abbreviations, it appeared on early chatrooms and forums.
It is hard to trace the exact origin of “smdh” as it is not nearly as prevalent as “smh” but it appeared on the internet sometime in the early 2000’s.
Urban Dictionary defined “smdh” in 2004 for the first time, setting the ground for its later spread on the web.
The appearance and growing popularity of social media sites has led to the widespread use of “smh” and “smdh”.
Today, it can be encountered on sites like Instagram, Twitter, Snapchat, as well as WhatsApp.