Usual small yardsticks (9)
I believe the answer is:
standards
'yardsticks' is the definition.
The answer and definition can be both man-made objects as well as being plural nouns.
Maybe there's a link between them I don't understand?
'usual small' is the wordplay.
'usual' becomes 'standard' (synonyms).
'small' becomes 's' (abbreviation - e.g. clothes size).
'standard'+'s'='STANDARDS'
Can you help me to learn more?
(Other definitions for standards that I've seen before include "Reference points for comparison" , "Touchstones, criteria" , "Flags; levels of quality" , "Principles of decent behaviour" , "Touchstones, reference points" .)