“SMH,” an abbreviation for “Shake My Head,” is a widely used acronym in conversations, expressing a range of sentiments from disappointment to disapproval. Employed primarily in response to shocking or hard-to-believe statements, it conveys a non-verbal gesture of disbelief, disappointment, or frustration.

Example

Person 1: Dude! John and Alex just got suspended from school yesterday.
Person 2: No way! SMH