1. a. A break in the continuity of a material object; a gaping chasm; an opening or aperture. Now rare.
3. Gram. and Pros. The break between two vowels coming together without an intervening consonant in successive words or syllables. Also attrib. and Comb., as hiatus-consonant, -filler, -glide; hiatus-filling adj.
The break or interval of silence is necessary in order that the two vowels may be separately heard, when there is no intervening consonant to mark the division between them.