hiat-; -hisc- +

(Latin: to stand open, to split; opening, aperture, gap; to yawn)

dehisce, dehisces, dehisced

1. To open at definite places, discharging seeds, pollen, or other contents, as the ripe capsules or pods of some plants.
2. To rupture or to break open, as a surgical wound.
3. To burst open, as capsules of plants; to gape.

In medicine: To burst open or to gape. A surgical wound may partially or completely dehisce after surgery, depending upon whether some or all of the layers of tissue come open.

Etymologically, when a peapod is ripe after a period of time and bursts open, it is considered "a yawning". The term dehisce comes from Latin dehiscere, "to split open", and from hiscere, "to gape, to yawn", from Latin hiare, "to yawn".

dehiscence

1. The spontaneous opening at maturity of a plant structure; such as, a fruit, anther, or sporangium, to release its contents.
2. The release of materials by the splitting open of an organ or tissue.
3. The natural bursting open of capsules, fruits, anthers, etc., for the discharge of their contents.
4. A rupture, bursting open, or splitting open, as of a surgical wound, or of an organ or structure to discharge its contents.
5. A premature bursting open or splitting along natural or surgical suture lines.

A complication of surgery that occurs secondary to poor wound healing. Risk factors include diabetes, advanced age, obesity and trauma during the post-surgical period.

From Latin dehiscere, "to split open"; from hiscere, "to gape, to yawn", from Latin hiare, "to yawn".

Information from A Word a Day about dehiscence

From: Lee Sataline, MD (leesataline1 AT cox.net)
Subject: dehiscence
The word dehiscence is one of the most vexing words in the surgeon's lexicon.
When a post-op patient "dehisses", one or more of the tissue layers of the incision have come apart. In a worst scenario, underlying organs (e.g. gut, lung, etc.) bulge out of the wound.
(In Shakespeare's Henry VI, the injured Clifford exclaims, "The air has got into my deadly wounds...") There are also non-surgical dehiscences that involve a tooth or the pharynx.
My favorite term from medical school—a long, long time ago—was Zuckerkandle's dehiscence, a defect in the skull's ethmoid bone.

—As seen in Wordsmith, Anu Garg; wsmith@wordsmith.org; AWAD (A Word a Day) Mail Issue 221; August 6, 2006.

dehiscent

1. Breaking open at maturity to release the contents.
2. Opening spontaneously at maturity to release seed.

hiant

1. Gaping; such as, a wound or laceration.
2. To open wide, as the margins of an incision or laceration.

hiatal

Relating to a hiatus.

For example, a hiatal hernia is an anatomical abnormality in which part of the stomach protrudes through the diaphragm and up into the chest. Although hiatal hernias are present in approximately 15% of the population, they are associated with symptoms in only a minority of those afflicted.

hiation

The act of gaping.

hiatopexy, hiatopexia

A surgical procedure to repair a space, gap, or widened opening; usually employing suture plication.

hiatus

1. A gape, "large opening" or interruption in space, time, or continuity; a break.
2. A gap or a break, pause, or cleft.
3. A slight pause occurring when two adjacent vowels in consecutive syllables are pronounced, as in "duality".
4. In anatomy, a separation, aperture, fissure, or short passage in an organ or body part; gap between structures.
5. In printing, a gap where something is missing, especially in manuscripts.
6. Etymology: a "breakd" or "opening in a material object", from Latin hiatus, "opening, rupture, gap", from hiare, "to gape, to stand open".

The sense, or meaning, of "gap" or "interruption in events", etc. was first recorded in 1613.

indehiscent, indehiscence

1. Not splitting open at maturity: indehiscent fruit.
2. Not opening spontaneously at maturity to release seeds; hard, dry, holding onto the seeds.
3. Lacking a distinct opening mechanism; spores shed by irregular rupture or breakdown of the capsule wall.

iris dehiscence

A defect of the eye characterised by multiple holes in the iris.

root dehiscence

A loss of the buccal or lingual bone overlaying the root portion of a tooth, leaving that area covered by soft tissue only.

Another gaping, yawning unit.