em·polder transitive verb orim·polder\ə̇m, em+\ (-ed/-ing/-s) Etymology: Dutch inpolderen, from in- in- (I) (akin to Old English in-) + polder — more at in-, polder : to make (land that is underwater or periodically flooded) cultivable by the erection of banks of levees to prevent or control inundation and by adequate drainage