Lions are fierce hunters. What the lion wants to eat, the lion eats. Let's hear "lion's share" used in a conversation.
Lion's Share 最大份额
Dan: Wow! We made a lot of money at our charity bake sale.
Anna: I know! We're rich! We're rich! We're rich!
Dan: You do know that the lion's share of the money will go to charity, right? We just keep a few dollars to pay for parking.
Anna: I know. I just want to act rich for a minute.
Dan: You know, real rich people don't do that with their money.
The lion's share is simply the largest part of something. This expression probably comes from the fact that a fierce lion is likely to take the most of whatever it wants.