1. Relating to, of the same nature as, or characterized by involuntary muscular contractions, esp. the long-continued contractions known as tonic spasms.
2. A person afflicted by such spasms; a person suffering from cerebral palsy.
Spasticating was first used from a not well known author called Crosta_ta. It is an adjective used when someone is faking to have a seizure to make your friends laugh.