1
general::
The greater part or most of something, as in Whenever they won a doubles match, Ethel claimed the lion's share of the credit, or As usual, Uncle Bob took the lion's share of the cake. This expression alludes to Aesop's fable about a lion, who got all of a kill because its fellow hunters, an ass, fox, and wolf, were afraid to claim their share. [Late 1700s]
American Heritage Idioms