A subarachnoid effusion of fluid in the spinal canal. ... Origin: rachio-+ G. Chysis, a pouring out ... (05 Mar 2000) ... 
Type: Term Pronunciation: rā′kē-ok′i-sis Definitions: 1. A subarachnoid effusion of fluid in the spinal canal.
rachiochysis 1. Leakage of cerebrospinal fluid from the spinal subarachnoid space. 2. Excessive formation or inflow of fluid into the spinal subarchnoid space.