Busy hospital in Eton failed to operate (2,3,2)
I believe the answer is:
on the go
'busy' is the definition.
(similar in meaning)
'hospital in eton failed to operate' is the wordplay.
'hospital' becomes 'H' (abbreviation for hospital).
'in' indicates putting letters inside.
'failed' indicates an anagram.
'to operate' becomes 'go' (synonyms).
'eton' anagrammed gives 'onte'.
'h' put inside 'onte' is 'onthe'.
'onthe'+'go'='ON THE GO'
(Other definitions for on the go that I've seen before include "Running around busily" , "Ever busy" , "Active and energetic" , "Very active (colloq.)" , "Active, always doing something" .)