Stake in Roman territory (4)
I believe the answer is:
ante
'stake' is the definition.
(stake in poker)
'in roman territory' is the wordplay.
'in' indicates a hidden word.
'ANTE' can be found hidden inside 'roman territory'.
(Other definitions for ante that I've seen before include "'Behind, before (4)'" , "early payment" , "Initial stake in a poker game" , "Stake (that may be upped?)" , "Preceding birth" .)