Old Arab nomad partially relishes a race north (7)
I believe the answer is:
saracen
'old arab nomad' is the definition.
(historical term for an Arab)
'partially relishes a race north' is the wordplay.
'partially' indicates a hidden word.
'SARACEN' can be found hidden inside 'relishes a race north'.
(Other definitions for saracen that I've seen before include "Ancient warrior" , "old Muslim back" , "British Army armoured people carrier" , "Arab (opposing the Crusaders)" , "Muslim defender in Crusades" .)