It swims in an arch around a circle (5)

I believe the answer is:

roach

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'it swims' is the definition.
The definition suggests a singular noun which matches the answer.

'in an arch around a circle' is the wordplay.
'in' means one lot of letters goes inside another.
'around' is an anagram indicator.
'a circle' becomes 'O' (O is a circle).
'arch' is an anagram of 'rach'.
'rach' placed around 'o' is 'ROACH'.

Can you help me to learn more?

(Other definitions for roach that I've seen before include "creepy-crawly" , "Swimmer" , "Silvery freshwater fish" , "Small freshwater fish related to carp" , "Maybe catch" .)

I've seen this clue in the Evening Standard.

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