Dictionary.com
Thesaurus.com

glottis vs. epiglottis

glottis
[glot-is] / ˈglɒt ɪs /

noun

Anatomy.
glottises, plural glottides plural

  1. the opening at the upper part of the larynx, between the vocal cords.

epiglottis
[ep-i-glot-is] / ˌɛp ɪˈglɒt ɪs /

noun

Anatomy.
epiglottises, plural epiglottides plural

  1. a thin, valvelike, cartilaginous structure that covers the glottis during swallowing, preventing the entrance of food and drink into the larynx.