(computing, graphical user interface, of a widget) Dropping down from above; being a specific type of selection control that hides its contents until activated.

(computing, graphical user interface) An instance of a selection object that hides the contents (especially the other choices) until activated.

plural of dropdown

(graphical user interface) A user interface control GUI element similar to a list box which allows the user to choose one value from a list.

plural of dropdown list