mating plug
A gelatinous secretion used in the mating of some species. It is deposited by a male into an orifice, such as the vagina, and later hardens into a plug or glues the tract together. While the plugs can be expelled afterwards, the male's sperm still gets a time advantage in getting to the egg if in the vagina, which is often the deciding factor in fertilization.
The following tags are aliased to this tag: sperm_plug (learn more).