Let's Compare Mucosa and Serosa. 1  MUCOSA VS.  Mucosa. The mucous membranes (or mucosae or mucosas; singular mucosa) are linings of mostly endodermal origin, covered in epithelium, which are involved in absorption and secretion. mucosa \mucosa\ n.
Definition of dropper for English Language Learners. : a glass or plastic tube that is used to measure out liquids by drops.
A drop-down list is a list in which the selected item is always visible, and the others are visible on demand by clicking a drop-down button. A combo box is a combination of a standard list box or a drop-down list and an editable text box, thus allowing users to enter a value that isn't in the list. An editable drop-down list is a combination of a drop-down list and an editable text box.