What does Boxing Day have to do with boxing?
glottis glot·tis (glŏt'ĭs)
n. pl. glot·tis·es or glot·ti·des (glŏt'ĭ-dēz')
The vocal apparatus of the larynx, consisting of the true vocal cords and the rima glottidis.
either the space between the vocal fold and arytenoid cartilage of one side of the larynx and those of the other side, or the structures that surround that space. See larynx.