SMH stands for 'shaking my head'. SMH is a popular expression used by people of all ages, and is often used in informal conversations. It is often used in text messages, emails, and social media posts to express a negative sentiment. It can also be used to express sarcasm or irony. SMH is often used in response to someone else's comment or opinion, or to express one's own opinion. It is an acronym used to express disbelief, disappointment, frustration, or disapproval. It is also used to express a general feeling of frustration or disapproval....