What is under the tongue; -- applied esp., in the higher vertebrates, to the twelfth or last pair of cranial nerves, which are distributed to the base of the tongue. -- n. One of the hypoglossal nerves called?

hypoglossal — Under the tongue; -- applied esp., in the higher vertebrates, to the twelfth or last pair of cranial nerves, which are distributed to the base of the tongue. -- n. One of the hypoglossal nerves. (Webster's 1913.)