1. Absence or lack of order; lack of coordination: Meg's cousin always refused to dance because of her sense of ataxia and feeling as if she had two left feet.
2. The inability of someone to be physically able to perform complex moves during muscle activity while making voluntary movements or when doing irregular muscular actions: Swimming proved to be difficult for Harriet's sister because of her ataxia and inability to move her arms and legs in coordinated and sequential movements.
3. Unsteadiness, incoordination or disorganization of movements in the absence of paralysis: For a few moments after getting off the Merry-Go-Round, Billy looked as if he were experiencing ataxia because he was staggering with dizziness and walking in an uncoordinated way.