Old sailors with invitation to go round duchy (8)
I believe the answer is:
cornwall
'duchy' is the definition.
(I've seen this before)
'old sailors with invitation to go round' is the wordplay.
I cannot really understand how this works, but
'old' could be 'o' (common abbreviation eg in OE for Old English) and 'o' is found within the answer.
'sailors' could be 'rn' (abbreviation for Royal Navy) and 'rn' is found within the answer.
'with' could be 'w' (abbreviation) and 'w' is located in the answer.
The remaining letters 'call' is a valid word which might be clued in a way I don't understand.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for cornwall that I've seen before include "County in SW England" , "Southwestern English county" , "Bodmin's county" , "County touching only one other" , "County of south-west England" .)