Fluid (5)
'fluid' is the definition.
(I know that fluid can be written as runny)
This is all the clue.
(Other definitions for runny that I've seen before include "Not set, inclined to spread" , "Of liquid consistency" , "(Of liquid) thin" , "(Exuding) liquid" , "Inclined to be rather liquid" .)
'fluid' is the definition.
(I know that liquid is a type of fluid)
This is all the clue.
(Other definitions for liquid that I've seen before include "In solution" , "Spendable" , "It flows freely" , "Non-gaseous fluid" , "Something like water or oil" .)
(Other definitions for spinal that I've seen before include "affecting the back?" , "sort of column" , "Of the vertebrae" , "Type of column" , "Relating to the backbone" .)