noun
: a gland that produces a viscid fluid which is extruded in filaments and on exposure to air hardens into silk: as
a. : either of a pair of greatly enlarged modified salivary glands of an insect larva that extend backward along the sides of the body and produce a compound filament from which is spun a larval or pupal cover (as a cocoon)
b. : any of two or more abdominal glands of a spider that open through spinnerets and produce a filament used chiefly in the spinning of webs