The lower part of the tympanic cavity. It is separated by a bony wall from the jugular bulb. ... (05 Mar 2000) ... 
(hi″po-tim´pә-nәm) the lower part of the cavity of the middle ear, in the temporal bone.
Type: Term Pronunciation: hī′pō-tim′pă-nŭm Definitions: 1. The lower part of the tympanic cavity. It is separated by a bony wall from the jugular bulb.