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.
The Dropper (Pipet) â¢ This tool is used to move very small amounts of liquid or to measure volume by counting drops. â¢ Hold the dropper upright and put the tip of the dropper in the liquid. Gently squeeze the bulb on the dropper to allow the water to fill the dropper.