Learn English – What word or phrase means “a loss of what was on your mind”

You're asking about three things: a gesture, an idiom, and showing someone the bird.

One gesture sometimes used in the U.S. to indicate "you're crazy" is pointing a finger at your temple, and turning it in a small circle a few times. I found one blogger who wrote, while this is rather benign in the U.S., it's regarded as highly offensive in some parts of Europe.

We express the meaning of that gesture by using terms like "you're crazy," "you're nuts," or even "you're loco," borrowing from the Spanish. "You're cuckoo" is also well-known (I guess a lot of cultures associate birds of some sort with a loss of sanity or judgement). The idiom "bats in the belfry" is well-understood, but not all that commonly heard; a few more popular idioms include, "has lost a few marbles," and "has a few loose screws;" I think the latter might be more likely to be applied to a single rash act (such as passing recklessly on the highway).

In the U.S., to "flip the bird" is to point your hand at someone with a raised middle finger. You might do this when they pass you unsafely on a roadway, but it hardly means "you're crazy!" (actually, it means "*F**** you!"). That gesture is considered vulgar and offensive; I'm don't know if someone would or could be prosecuted on the roadway, but it evidently does violate obscenity laws when broadcast on television.

Net profit is a proper definition or net financial result:

• Often referred to as the bottom line, net profit is calculated by subtracting a company's total expenses from total revenue, thus showing what the company has earned (or lost) in a given period of time (usually one year). also called net income or net earnings.

Source: (www.investorwords.com)