In organic synthesis, you will find frequently find "wash" in a sentence like,
"The compound was dissolved in ethyl acetate, washed with water, aqueous sodium bicarbonate, and brine (or saturated sodium chloride), dried over MgSO4, filtered and stripped."
In that case, yes, you put your solution of compound and ethyl acetate in a sep funnel; add water, shake, remove the water; add sodium bicarbonate solution, shake, and remove the bicarbonate solution; then add brine, shake and remove the brine. The water wash will remove any water soluble impurities; the sodium bicarbonate wash will remove acidic species or ensure that any amines are in their free base form; and the salt wash will remove most of the remaining water dissolved in the ethyl acetate. Final traces of water are removed by the MgSO4.