Stupid clot with poor etiquette (8)
I believe the answer is:
protocol
'etiquette' is the definition.
(protocol is a kind of etiquette)
'stupid clot with poor' is the wordplay.
'stupid' is an anagram indicator (in a stupid order).
'with' means one lot of letters go next to another.
'clot' put after 'poor' is 'poorclot'.
'poorclot' anagrammed gives 'PROTOCOL'.
(Other definitions for protocol that I've seen before include "rules of behaviour" , "Draft treaty" , "Code of conduct, etiquette" , "Good form" , "Formalities" .)