oc·​clu·​sion | \ ə-ˈklü-zhən How to pronounce occlusion (audio) \

Definition of occlusion

1 : the act of occluding : the state of being occluded: such as
a : the complete obstruction of the breath passage in the articulation of a speech sound
b : the bringing of the opposing surfaces of the teeth of the two jaws into contact also : the relation between the surfaces when in contact
c : the inclusion or sorption of gas trapped during solidification of a material
2 : the front formed by a cold front overtaking a warm front and lifting the warm air above the earth's surface

What Do the Words occlusion, recluse, seclusion, and exclude Have in Common?

Occlusion is a descendant of the Latin verb occludere, meaning "to close up." Occludere in turn comes from the prefix ob-, here meaning "in the way," and the verb claudere, meaning "to close or shut." Occlusion is one of many English terms derived from claudere. Some others are recluse, seclusion, and exclude. An occlusion occurs when something has been closed up or blocked off. Almost all heart attacks are the result of the occlusion of a coronary (heart) artery by a blood clot. When a person's upper and lower teeth form a malocclusion, they close incorrectly or badly. An occlusion, or occluded front, happens when a fast-moving cold front overtakes a slow-moving warm front and slides underneath it, lifting the warm air and blocking its movement.

Examples of occlusion in a Sentence

Recent Examples on the Web Outcomes are variable: while many patients regain a degree of vision, there are no reliable treatments for whole-eye vision loss due to a retinal vascular occlusion. Zachary Snowdon Smith, Forbes, 14 Apr. 2022 Retinal vein occlusion is linked to diabetes, high blood pressure, fatty buildup in the arteries and eye disorders like glaucoma. Zachary Snowdon Smith, Forbes, 14 Apr. 2022 One rare but serious risk of getting filler is vascular occlusion, which happens when a provider accidentally injects the filler into a blood vessel. Kaitlin Clark, Allure, 9 Feb. 2022 Sometimes, games only support an additional pass of ambient occlusion or shadows—which makes sense because a full ray tracing system can break pre-baked lighting systems and other engine elements. Sam Machkovech, Ars Technica, 7 Dec. 2021 In addition to follicular occlusion, meaning the hair follicles become blocked and then ruptured, the development of hidradenitis suppurativa is also associated with having some kind of inflammation in the body, Dr. Sayed explains. Sara Gaynes Levy, SELF, 17 Feb. 2022 Should a patient begin to show any red-flag symptoms of vascular occlusion. Kaitlin Clark, Allure, 9 Feb. 2022 Sometimes, a doctor may recommend applying this with occlusion—this means wearing gloves or wrapping the hands, ideally to allow the medication to better penetrate. Rachel Nall, Msn, SELF, 7 Feb. 2022 The biggest difference comes from a large boost to shadow resolution and quality, whether in the form of higher-res shadow maps, more objects casting significant shadows, or a fuller, richer pass of ambient occlusion across more surfaces. Sam Machkovech, Ars Technica, 12 Jan. 2022 See More

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'occlusion.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

First Known Use of occlusion

circa 1645, in the meaning defined at sense 1

History and Etymology for occlusion

Latin occludere

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Time Traveler for occlusion

Time Traveler

The first known use of occlusion was circa 1645

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Last Updated

12 Jun 2022

Cite this Entry

“Occlusion.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/occlusion. Accessed 29 Jun. 2022.

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More Definitions for occlusion


oc·​clu·​sion | \ ə-ˈklü-zhən How to pronounce occlusion (audio) \

Medical Definition of occlusion

1 : the act of occluding or the state of being occluded : a shutting off or obstruction of something a coronary occlusion especially : a blocking of the central passage of one reflex by the passage of another
2a : the bringing of the opposing surfaces of the teeth of the two jaws into contact also : the relation between the surfaces when in contact
b : the transient approximation of the edges of a natural opening occlusion of the eyelids
3 : sorption especially : sorption of gases

More from Merriam-Webster on occlusion

Nglish: Translation of occlusion for Spanish Speakers

Britannica English: Translation of occlusion for Arabic Speakers


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