Party official entertains Arab head of state in frigate? (7)
I believe the answer is:
warship
'frigate?' is the definition.
(frigate is a kind of warship)
'party official entertains arab head of state' is the wordplay.
'party official' becomes 'whip' (I've seen this before).
'entertains' is an insertion indicator.
'arab' becomes 'ar' (abbreviation in Chambers).
'head of' indicates taking the first letters.
The initial letter of 'state' is 's'.
'ar'+'s'='ars'
'whip' going around 'ars' is 'WARSHIP'.
'in' is the link.
(Other definitions for warship that I've seen before include "Naval asset" , "Eg, destroyer, cruiser" , "It's armed at sea" , "Navy asset" , "Fighting vessel" .)