"Hey, that plant there is kind of shaped like my balls," is something that you're really not allowed to say in polite society. It wasn't always that way, though.
As it turns out, many of the words you use every day were invented by people who had wieners, balls and asses on the brain. Yes, we're serious. For example:

What It Means Now:
An over emotional reaction, chaos, a Def Leppard album.
The Dirty History:
The term comes from the Greek "Hystera," which means womb or ovary, which also gives us the term hysterectomy. Modern examples of hysteria are mostly riot related, but back in the Victorian era, it was considered a nervous condition for females, caused by their lady-parts. Which, like riots, was stopped with fucking fire hoses.

That image shows the so-called "water massage" that was used to treat the condition. For women who didn't like being shot in the crotch with a jet of high-pressure water, the doctor could use his fingers to create the same mysterious effect, which they referred to as "hysterical paroxysm" before someone explained to them what an orgasm was.

What It Means Now:
A type of flower.
The Dirty History:
At some point in history a botanist was looking at what is widely considered to be the most beautiful flower in existence when he noticed that the roots sort of looked like balls.

It's unknown if he held the flower next to his crotch, pointed and laughed, but the observation stuck, and the plant was named for a ball-joke.
The term orchid comes from the Greek, orkhis, which means testicle. This etymology of orchid makes the White Stripes lyrics, "You took a white orchid and turned it blue" make much, more sense.

What It Means Now:
A group of experts speaking to a usually bored audience, or a certain kind of intensive college course.
The Dirty History:
Seminar comes from the Latin term, "Seminis" which means semen. This is used figuratively because it is a spawning ground for ideas, although it can definitely be taken literally, according to this porno we saw one time.

Nope. You're thinking of "seamen." It's the other kind.
Likewise if you ever hear some important person referring to a "seminal" moment or idea, same thing. It's the ejaculation that gave birth to something new.
OK, we admit it also means "seed" but the word comes from Old French. If it's the French we're talking about, which do you think they were referring to?