Mandeville's travels : the Cotton version
Mandeville, John, Sir., British Library. Manuscript. Cotton Titus C.16.
Hamelius, Paul, 1868-1922.

clepen flessch þere Dabago, etc.—Brussels 10420-5: La appellent ilz la char dalbago et le vin vape. So in B. 11141. H. has Dabago and Vapa. Sir G. Warner, following the Egerton MS., which omits all mention of wine and meat, tries to interpret these two words as place names. But vappa is only the Latin for flat wine, as in Massinger's Believe as you list:

………. Your viper wine,
So much in practice with grey-bearded gallants,
But vappa to the nectar of her lips.

(Act IV, Scene 1.)

As for dalbago, it bears some resemblance to albacore, explained in the Oxford English Dictionary as meaning a certain fish, andPage  2:92 derived from Arabic al + bukr, pl. bakārat, a young camel, a heifer.