Meaning

• A gap in a series, making it incomplete.

• An interruption, break or pause.

• An unexpected break from work.

• A gap in geological strata.

• An opening in an organ.

  "Hiatus aorticus is an opening in the diaphragm through which aorta and thoracic duct pass."

• A syllable break between two vowels, without an intervening consonant. (Compare diphthong.)

  "Words like reality and naïve contain vowels in hiatus."