Outfit, uniform or clothes showing precision (6)
I believe the answer is:
rigour
'precision' is the definition.
The definition and answer can be both human attributes as well as being singular nouns.
Maybe you can see an association between them that I don't see?
'outfit uniform or clothes' is the wordplay.
'outfit' becomes 'rig' (synonyms).
'uniform' becomes 'U' (phonetic alphabet: alpha, bravo, charlie etc.).
'clothes' is an insertion indicator (some letters clothe or cover others).
'u' put within 'or' is 'our'.
'rig'+'our'='RIGOUR'
'showing' is the link.
Can you help me to learn more?
(Other definitions for rigour that I've seen before include "Severity, harshness" , "Trial" , "Hardship" , "Austerity - strictness" , "Extreme strictness" .)