gubernaculum

noun5

1. •
   A part or structure that serves as a guide.
2. •
   Either of a pair of folds of peritoneum which connects the caudal end of the fetal testis with the bottom of the scrotum in a male fetus, and by failing to elongate in proportion to the rest of the fetus causes the descent of the testis into the scrotum; or an analogous cord of connective tissue attached to the ovary in a female fetus, which is the precursor of the round and ovarian ligaments.
3. •
   (more fully gubernaculum dentis) A cord or sheath of connective tissue that connects the sac of an unerupted permanent tooth with the surface of the gum.
4. •
   The reproductive tract of an invertebrate, or part of it; especially the section containing the gonophores (in a hydrozoan); a sclerotized structure in the cloaca (in a nematode).
5. •
   (rare) A trailing flagellum in certain protists used for steering.