Uglier Than Sin:
Old expression, refers to sin in the context of obscenity.
Uglier than sin, and twice as expensive.
Under the weather:
Refers literally to seasonal illnesses, but generally means feeling unwell.
Fred's a bit under the weather, and won't be coming in today.
Unmentionable, unspeakable (concept):
These expressions are based on social concepts of things not discussed in polite society. They have some individual contexts, like unmentionables as an old term referring to underclothes, but in general modern usage, refer to something terrible, but deliberately not specified.
The unspeakable, in pursuit of the uneatable. (Oscar Wilde, referring to fox hunts.)
Unsung (person, event, action):
A person or group not given due credit.
The unsung heroes of the office Christmas party were the data entry people.
An understood and generally accepted social custom, having the force of law in terms of being observed by all.
It was an unwritten law in the office that you just didn't wake Fred up after lunch.
Up a blind alley:
Following a path which leads to an unknown destination, or sometimes dead end.
The whole marketing campaign seems to have gone up a blind alley, here.
Use Your… Noodle, Noggin, Nut,:
The human brain has a lot of idiomatic metaphors, and some are quite obscure. The actual words are quite dated, not usually used in modern parlance, but continue to exist in idioms.
Use your noggin, that's a car, not a screwdriver!
Van Gogh's ear for music:
Van Gogh's famous cutting off of his own ear in an argument with his friend Paul Gauguin is well known, hence the reference to Van Gogh's ear when referring to someone who's not listening, or doesn't seem to hear properly.
He's got Van Gogh's ear when it comes to melody.
Variety Is The Spice Of Life:
Very old, hackneyed, expression, referring to diversity and variety in life as stimulating the taste of life.
Variety is the spice of life… so what are we doing here, again?
Wag the Dog:
The complete expression, which is often contracted in various ways, is The Tail Wagging The Dog. Obviously, this is the opposite of the normal process, which is the context of the idioms.
This is the fleas wagging the dog, in my opinion.
The desire to travel, abstracted into this word as part of an idiom.
Wanderlust will drive people around the world, in some cases.
Water Under The Bridge:
The exact idiom is that water which has flowed under a bridge has moved on. Hence the context, which means something described as water under the bridge has passed.
Look, it's all water under the bridge now. Get over it, for your own sake.
Wear And Tear
This is actually a legal expression, as well as an idiom. The idiom means natural attrition of the condition of a thing. Wear and Tear, in terms of business hire or rental, means expected deterioration over time, for which the hirer or renter isn't considered liable. When applied to people, the idiom means the effects of experience.
George is looking like he's had some wear and tear, recently.
Wear Your Heart On Your Sleeve:
To be very open, perhaps too open, about your feelings in public.
Poor Joan, wearing her heart on her sleeve like that!
Wearing The Scars:
This is a metaphoric idiom, but in some cases it's a double metaphor, where the obvious outer scars aren't those being referred to.
He's wearing a few scars that you could only see if you knew him well.
This idiom has a social context, but also had at one point a class context. A well bred person was considered one of the upper class. In modern terms, it means a person with good manners and social grace.
Fred is very well bred, really knows his way around any group of people.
Literally means well dressed, sometimes refers to a social group of the best people in society.
He was always at home among the well heeled, wealthy, and powerful.
A person who acts like a damper on a happy occasion. Wet blankets are usually used to put out fires, and aren't recommended for sleeping in.
I know he didn't intend to be a wet blanket, but he's so good at it.
The original expression is Madder Than A Wet Hen, which is now virtually meaningless as a literal statement, but means emotionally upset and vocal.
She was being a real wet hen, running around complaining.
When It Rains, It Pours:
When something happens at all, it happens to excess.
When it rains, it pours, I see; more work than we could do in a year, there.
When Pigs Fly :
Pigs aren't very likely to be flying animals. Hence the expression, which means when the impossible happens.
We'll get new staff when pigs fly, and not before.
Wicked (thing, situation):
New Zealand expression, meaning good, as one of the antonymic inversions of the original meaning of the word as the idiom.
Free beer! Wicked!
Wild and Woolly:
Something that looks wild, uncontrolled.
It was a really wild and woolly pub, some of the people looked utterly mad.
Wild- Child, Man Woman or Thing:
Old Celtic expression revived in the 20th century. Originally meant a person of the wilds, living outside society. Now means a person living outside social norms, often a celebrity.
She's the definitive Wild Child of the current generation of musicians.
Wine and Dine:
A romantic engagement by implication.
She seems to be able to find people to wine and dine her in caves.
Originally a legal expression, now commonly used to mean without any bias or personal interest.
My opinion, without prejudice, is that he's always been an idiot.
From Shakespeare's famous statement Hell hath no fury like a woman scorned. Now applied to a woman whose feelings have been ignored or abused.
She's a woman scorned, and here comes the fury, I'd say.
Worth A Damn:
Worth caring about. Something is, or isn't, worth a damn, in the idiomatic context of the statement.
These so called unsolicited testimonials aren't worth a damn.
Directed the wrong way, or to the wrong conclusion.
They gave us a completely wrong steer on that deal.
Advertising idiom, (originally there was actually a Brand X) meaning an unknown, inferior brand compared to the sponsor's product.
This looks very Brand X to me.
From the Greek, meaning outside. While retaining its original meaning, the word is now becoming an idiomatic usage in relation to sciences, which is enlarging its frame of reference.
I'd go out with him, but xeno biology wasn't one of my subjects.
X marks the spot:
From old pirate stories, X was the spot on the map where the treasure was buried. The idiomatic usage is so common that it's now a fully understood idiom in its own right.
Hmmm… Audit reports, bills, lawsuits… X marks the spot where we find some actual figures, for once, I assume?
You Are What You Eat:
What you eat determines your nature. Variously used to describe people, diets, and their characteristics.
Well, if you are what you eat, why are you eating that?
You Can't Judge A Book By Its Cover:
External appearances don't tell the whole story.
Don't judge him by his cover, he looks like a kid's coloring book, but he's more like Britannica.
You Can't Take it With You:
Old saying referring to material possessions in the afterlife.
You can't take it with you, but knowing you, I know you'll at least try.
The use of zero in an idiom indicates the value of the subject is set at nothing. It can be a serious insult, applied to a person.
In my opinion his reputation equates to one large zero