/ˈreərɪfaɪ/ (verb)

Definition

to make something sparser or thinner, thin, attenuate, dilute, lighten, water down, make or become less dense, weaken – make something more refined

Example

Generally, prolonged stay at high altitudes as a part of adventure sport or country’s defense means living in stressful environment leading to a need to study the effects of such an alien locale. The most significant and connatural factor of high altitudes is hypoxia. Hypoxia or rarefied atmosphere with low oxygen availability affects both physical and mental performances of people because oxygen is even more essential to life than food and water.

Source: https://www.sciencedirect.com/

Antonyms

thicken, intensify, condense

Parts of speech

Adjective: rarefiable

Adjective: rarefied

/hɜːˈmet.ɪk/ (adj)

Definition

airtight, so densely and tightly fitting that no air can penetrate or pass through, watertight, impervious, tightly sealed, waterproof, impenetrable, closed, enclosed, confined

Example

Ever find yourself craving pickles but when you reach for your favorite jar of dills, you can’t pry it open no matter how hard you grip? You twist and turn and, in the end, you’re out of breath and without your favorite snack. Well, when brute force has failed, give these ideas a go.

Often all that is needed is improving your grip on the jar lid. A loose grip could be caused by the lid being damp, or perhaps it’s simply shiny and slippery.

Items that can be used for greater grip include a dry dish towel, piece of silicone (often found in kitchens as a heat-resistant mat or shelf liner), or plastic wrap. Place the grip-assisting item over the lid of the jar and twist as you usually do and turn a slippery lid into an open one. You can also improve your grip by donning a pair of rubber gloves, or placing a thick rubber band around the lid.

Source: https://www.tasteofhome.com/

Antonyms

unsealed, open

Parts of speech

Adverb: hermetically

/əʊˈpeɪk/ (adj)

preventing light from passing or getting through, filmy, impervious, fogy, misty, dense, misty, muddy, hazy, murky, blurred, smoky, cloudy – unclear and difficult to understand, impenetrable, obscure, incomprehensible, nebulous

De-lamination and “milkiness” can impact negatively upon the quality of windscreens. Delamination occurs when one or both of the layers of the glass separate from the polyvinylbutyrate interlayer. This can cause different optical effects. Milkiness occurs when the polyvinylbutyral layer separates from the layers of glass and starts to return to its original prelaminated state. The windscreen can start to become opaque and cause difficulty for the driver.

Source: https://www.monash.edu/

Antonyms: transparent, translucent, diaphanous, clear

Noun: opacity

Noun: opaqueness

Adverb: opaquely

Dense 504 Absolutely Essential Words Lesson 4

/dents/ (adj)

including so much matter in a small place, difficult to penetrate, thick, close together, tightly packed, solid, crowded, compact, impenetrable, impassable, murky, concentrated, condensed – obscure, opaque, elusive

Many of the world’s small island or isolated states have large populations for their size. Macao, Monaco, Singapore, Hong Kong and Gibraltar are the five most densely populated. Singapore has nearly 8,000 people per km2 – more than 200 times as dense as the US, and 2000 times that of Australia.

Source: https://ourworldindata.org/

Antonyms: sparse, clear, transparent

Noun: density

Adverb: densely

Verb: densify

Noun: denseness