Safeguard European nurse somehow (6)
I believe the answer is:
ensure
'safeguard' is the definition.
(I've seen this in another clue)
'european nurse somehow' is the wordplay.
'european' becomes 'e' (abbreviation e.g. EU).
'somehow' indicates an anagram.
'nurse' anagrammed gives 'nsure'.
'e'+'nsure'='ENSURE'
(Other definitions for ensure that I've seen before include "Make certain that (something occurs)" , "Make certain or safe" , "Protect" , "Guarantee" , "Make certain for the future" .)