what does smh mean

what does smh mean

what does smh mean

according to onlinedictionary.com
acronym for "shaking my head".

according to urbandictionary.com
smh 
Acronym for 'shake my head' or 'shaking my head.' Usually used when someone finds something so stupid, no words can do it justice. Sometimes it's modified to 'smfh' or 'smmfh' by those that prefer profanity in their internet acronyms.
trick1: i got a headache...i hit myself in the head with my knee while trying to do situps.