is a specific kind of: opening, orifice, porta.

is a broader term that covers: mouth, oral cavity, oral fissure, rima oris | pudendal cleavage, pudendal cleft, pudendal slit, rima pudendi, rima vulvae, urogenital cleft, vulvar slit | glottis vera, rima glottidis, rima vocalis, true glottis | false glottis, glottis spuria, rima respiratoria, rima vestibuli.