means Small pieces of paper or plastic with a sticky back, designed to be pressed onto surfaces for decoration, labeling, or fun.

from From the verb "stick" — to adhere or cling — which traces back to Old English "stician," meaning to pierce or remain fixed, with cousins across the Germanic languages (German "stechen," to prick). The "-er" suffix simply names the thing that does the sticking. The word for the gummed paper kind is modern, riding in on the wave of cheap adhesives and printing, but the root is ancient: long before glue, things that "stuck" were things that jabbed in and stayed put.