Meter made by Siemens went round (6)
I believe the answer is:
speedo
'meter' is the definition.
Both the definition and answer are singular nouns.
Maybe there's an association between them I don't understand?
'by siemens went round' is the wordplay.
'by' says to put letters next to each other.
'siemens' becomes 's' (synonyms).
'went' becomes 'peed' (both can mean urinated).
'round' becomes 'o' (round can mean a round object).
's' next to 'peed' is 'speed'.
'speed'+'o'='SPEEDO'
'made' is the link.
Can you help me to learn more?
(Other definitions for speedo that I've seen before include "one gives you the going rate" , "The clock (in a car)" , "Mph indicator" , "Make for swimmers" , "Car mph/kph indicator" .)