1) Descent 
• (n.) The act of stumbling, rocking, or rolling; a reeling.
1. A staggering or stumbling in trying to walk. ... 2. A tremor or shaking of the head, of cerebellar origin. ... Origin: L. Titubo, pp. -atus, to stagger ... (05 Mar 2000) ... 
(tit″u-ba´shәn) the act of staggering or reeling; a staggering gait with shaking of the trunk and head, commonly seen in cerebellar disease.
Tit`u·ba'tion noun [ Latin titubatio : confer French titubation .] The act of stumbling, rocking, or rolling; a reeling. Quain. 
Type: Term Pronunciation: tit′ū-bā′shŭn Definitions: 1. A staggering or stumbling in trying to walk. 2. A tremor or shaking of the head, of cerebellar origin.