Insidious is an adjective meaning:

1. Working or spreading harmfully in a subtle or stealthy manner: insidious rumors; an insidious disease.
2. Intended to entrap; treacherous: insidious misinformation.
3. Beguiling but harmful; alluring: insidious pleasures.

Insidious is also the title of a 2010 horror film starring Patrick Wilson, Rose Byrne and Ty Simpkins. According to IMDB: “A family looks to prevent evil spirits from trapping their comatose child in a realm called The Further.” Seems likely that a haunted house could provide a steathily-spreading evil.

Relatedly, an insidious disease is “a disease existing, without marked symptoms, but ready to become active upon some slight occasion; a disease not appearing to be as bad as it really is.”

Insidious Disease is also, appropriately enough, a death metal band:

If you ask INSIDIOUS DISEASE about their definition of death metal they would probably answer that it should satisfy your urge for darkness, the morbid and the sick, the perverted and the twisted, all things insane that can be discovered within the human mind and soul manifesting in a sound that makes you vomit your guts out!

Don’t confuse insidious with the similar-sounding invidious, which means:

1. Tending to rouse ill will, animosity, or resentment: invidious accusations.
2. Containing or implying a slight; discriminatory
3. Envious.

Use insidious for creeping, slow-moving evil, and invidious for actions done by humans that are immediately obvious as being harmful. Racist speech is invidious, and the lingering effects of racism have insidious effects on people’s lives.

Recently, a student saw the word swagger in a GRE problem and began to laugh.

“Why is that funny?” I asked.

“I didn’t know that was a real vocab word,” she said. “I thought it was only for rap videos.”

Fantastically, swagger is actually a perfectly GRE appropriate word, and has been around much longer than hip-hop has even existed.

Swagger means “To walk or conduct oneself with an insolent or arrogant air; strut.”

Some other types of walking that might occur on the GRE include:

Sashay: To walk or proceed, especially in an easy or casual manner; To strut or flounce in a showy manner.

Amble: To walk slowly or leisurely; stroll.

Lumber: To walk or move with heavy clumsiness; To move with a rumbling noise.

Perambulate: To walk through; To inspect (an area) on foot; To walk about; roam or stroll.

Circumambulate: To walk around (something), especially as part of a ritual.

//www.youtube.com/watch?v=5cDLZqe735k

Thanks to Bobby Brown, “prerogative” is one of the most mispronounced words in English — as you can hear in the video, Mr. Brown pronounces the word “PER-ogative.” (Click the audio icon on this page for a correct pronunciation).

Britney Spears repeats the error:

//www.youtube.com/watch?v=dIOH8Trfas4

A prerogative is an exclusive right or privilege held by a person or group, or the exclusive right and power to command, decide, rule, or judge.

According to Thesaurus.com:, “a privilege is a right that may be extended to a group or a number of people; a prerogative is a right that, customarily, is vested in a single person.”

It is the boss’s prerogative to determine the office supply budget.

While it is the prerogative of pop stars to pronounce words however they like in their videos, it is the prerogative of lexicographers to record the correct pronunciations of words in dictionaries.

The words warrant and license can be used in somewhat similar ways, although they are milder than prerogative.

The anti-death penalty activist argued that violence is not a warrant for future violence.

The pronunciation activist argued that fame does not give one license to butcher the English language, even if slightly improving the nation’s collective vocabulary in the process.

“Origin story” is an expression for a superhero’s backstory — for instance, Superman was born on Krypton just before it was destroyed. Many words also have fascinating origin stories. While English comes largely from Latin (and from Greek, and from Latin through French and Spanish, with some Germanic roots and a bit of Sanskrit, etc.), you’ll find that word usage can change quite bit over a couple thousand years.

Supplant means “take the place of, displace, especially through sneaky tactics.”

In the 1950s, many people took cod liver oil as a health supplement. Today, fish oil capsules and flaxseed oil have supplanted the smelly old standby our grandparents used.

He did achieve his dream of becoming CEO, but only after supplanting our previous CEO by wresting control while she was battling cancer.

Some related words are:
Outstrip (surpass, exceed; be larger or better than; leave behind)
Overshadow (cast a shadow over, make to seem less important)
Supersede (replace or cause to be set aside)
Eclipse (obscure, darken, make less important)

Supplant comes from the Latin for to trip up (planta meant the sole of the foot). To supplant something is like a more mature version of sticking your leg out into the aisle so someone falls on his face.

The same root, “planta”, appears in the foot condition plantar fasciitis.

Here’s something a prodigious lexicon is good for — naming nail polish colors when you’ve got 55 shades of “pink.”

If you are wont to frequent nail salons, you may have noticed that many of the color names involve puns (and often are not terribly descriptive of the color they purport to represent): Tart Deco, Lapis of Luxury, Pinking Up the Pieces, and my favorite … Sand of a Beach.

A few color names, however — currently in the Essie line — sport more erudite names containing GRE vocabulary words:

Demure Vixen

Demure means “characterized by shyness and modesty; reserved.” Culturally, demure is almost always used to describe women. A word that also means “reserved” and is often used to describe men is staid.

Interestingly, demure can also mean “affectedly or coyly decorous, sober, or sedate” — that is, faking being shy and reserved as a flirtation strategy. That makes more sense when paired with vixen, a female fox or what the dictionary describes as “an ill-tempered or quarrelsome woman,” a usage that has since fallen out of fashion. Vixen is often used in a fashion and pop culture context to describe a femme fatale or audaciously appealing woman. (This word is a bit too sexy for the GRE, though).

Vermillionaire

What a keen pun! Vermillion is a bright red to reddish-orange color.

Going Incognito

Incognito means undercover: “having one’s identity concealed, as under an assumed name, especially to avoid notice or formal attentions.”

Incognito shares the root cog (to know) with many words relating to knowledge, such as cogent, cognition, cognitive, cognizant, and reconnaissance.