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.
Definition of dropper. 1  1 : one that drops. 2  2 : a short glass tube fitted with a rubber bulb and used to measure liquids by drops âcalled also eyedropper, medicine dropper.