Romanian word dubla comes from Latin pleo (To fill, to fulfill.), Late Latin duplo

Detailed word origin of dubla

Dictionary entry	Language	Definition
pleo	Latin (lat)	To fill, to fulfill.
duplo	Late Latin (LL)
duplus	Latin (lat)	Double (twice as much, or as big).
duplo	Latin (lat)	(Late Latin) I double.
dūplāre	Late Latin (LL)
dobler	Old French (fro)	(ambitransitive) to double. (by extension) to increase dramatically.
doubler	French (fra)	(Belgium) to repeat a school year. To double, duplicate. To double-cross. To dub. To overtake, pass.
dubla	Romanian (ron)	To double.

Words with the same origin as dubla