Yours, Etc.: Origins and Uses of 8 Sign-Offs
1560s, "break or opening in a material object," from Latin hiatus "opening, aperture, rupture, gap," from past participle stem of hiare "to gape, stand open" (see yawn (v.)). Sense of "gap or interruption in events, etc." is first recorded 1610s.
hiatus hi·a·tus (hī-ā'təs)
n. pl. hiatus or hi·a·tus·es
An aperture or fissure in an organ or a body part.
in prosody, a break in sound between two vowels that occur together without an intervening consonant, both vowels being clearly enunciated. The two vowels may be either within one word, as in the words Vienna and naive, or the final and initial vowels of two successive words, as in the phrases "see it" and "go in." Hiatus is the opposite of elision, the dropping or blurring of the second vowel; it is also distinct from diphthongization, in which the vowels blend to form one sound