Fluid (5)
'fluid' is the definition.
(synonyms)
This is the entire 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.
(synonyms)
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" .)