Stimming is a repetitive body movement, such as hand flapping. The term is shorthand for self-stimulation. Repetitive movement, or stereotypy, is often referred to as stimming under the hypothesis that it has a function related to sensory input.
See also 
- ^ Nind M, Kellett M (2002). "Responding to individuals with severe learning difficulties and stereotyped behaviour: challenges for an inclusive era". Eur J Spec Needs Educ 17 (3): 265–82. doi:10.1080/08856250210162167.