Professional brings in editor: a Spaniard? (5)
I believe the answer is:
pedro
'a spaniard?' is the definition.
(I've seen this before)
'professional brings in editor' is the wordplay.
'professional' becomes 'pro' ('pro' can be a synonym of 'professional').
'brings in' indicates putting letters inside.
'editor' becomes 'ed'.
'pro' placed around 'ed' is 'PEDRO'.
(Other definitions for pedro that I've seen before include "Common Spanish name" , "Five" , "Mexican perhaps" , "Spaniard" , "Spanish for Peter" .)