Engineer relaxing in Minorca (7)
I believe the answer is:
marconi
'engineer' is the definition.
(Guglielmo Marconi)
'relaxing in minorca' is the wordplay.
'relaxing in' indicates an anagram (the original order of the letters is relaxed).
'minorca' with letters rearranged gives 'MARCONI'.
(Other definitions for marconi that I've seen before include "Wireless inventor from Minorca" , "Italian inventor of radio" , "Developer of radio-telegraphy" , "Radio engineer" , "Developer of radio telegraphy" .)