Groups set step out (7)
I believe the answer is:
septets
'groups set step out' is the definition.
'septets' can be an answer for 'groups' (I have seen 'Groups of seven ' mean 'septets' so perhaps 'groups' could also mean 'septets'). I'm not certain of the 'set step out' bit.
'set step out' is the wordplay.
'out' indicates an anagram (out can mean wrong or inaccurate).
'set'+'step'='setstep'
'setstep' anagrammed gives 'SEPTETS'.
Can you help me to learn more?
(Other definitions for septets that I've seen before include "Musicians" , "Groups of seven" .)