Process messy fluid: about time (6)
I believe the answer is:
system
'process' is the definition.
(I've seen this before)
'messy fluid about time' is the wordplay.
'fluid' is an anagram indicator.
'about' indicates putting letters inside.
'time' becomes 't'.
'messy' with letters rearranged gives 'sysem'.
'sysem' placed around 't' is 'SYSTEM'.
(Other definitions for system that I've seen before include "Plan of action" , "Method of working" , "Group of interrelated elements comprising a unified whole" , "A complete set of procedures for doing something" , "Method (of betters?)" .)