If someone takes the lion's share, it's safe to say there's not going to be much left for everyone else.
But why does it have to be the "lion's" share? Why not the tiger's or the bear's?
You can blame Aesop for this one.
The story behind this idiom seems to go back to Aesop's fables. The gist of the story is the lion goes out with some other animals to go hunting, and when they're divvying up their catch, the lion takes the first share.
Seems pretty reasonable since, after all, the lion is the king of the jungle. But then the lion goes on to take the other shares, for a variety of reasons and with a variety of threats.
By the time this phrase comes into English in the 18th century, its meaning has changed. It no longer means to take everything, but instead means to take most of something or the principle parts.
Most of what though?
A lot of the examples that pop into your mind probably have something to do with money -- the lion's share of the profits, the lion's share of the budget, the finances, the taxes, etc.
But according to the Corpus of Contemporary American English, people use "lion's share" to talk about all kinds of things. The lion's share of attention, of work, of responsibility, of blame, of refugees, of blog posts. Anything, really.
That takes care of the "lion" half of this expression, but what about "share?"
This term goes back to Old English, and originally means "a division." A "land share" was a division of land. "Share" later comes to mean a portion of something allotted to someone or the portion that someone contributes.
Around the 16th century, English speakers turn "share" into a verb that means to divide or apportion something into shares. This is where we get the more general meaning of possessing something together or occupying something together -- basically, what your kindergarten teacher taught you to do.
There's another, more recent meaning for share, and that's to confess or to talk about something.
According to the Oxford English Dictionary, we began "sharing" our thoughts and feelings in the 20th century. It's likely we were already talking our thoughts and feelings before that moment, but we didn't describe it as "sharing."
Are there other idioms that you've always wanted to pick apart? Share them with us at firstname.lastname@example.org or email@example.com.