A big, furry brown cat, found in the savvanna of Africa. NOT the jungle, you phyco's. Often toated as the king of beasts, and no one knows why. Some say that the lion is the biggest cat, even though the tiger is the biggest cat in the world. Often hunted for trophies.

a lion is the second largest feline,next to the tiger, they live in africa in the savannah and some live in more wooded areas
Male lions are much larger than female lions but the female lions do all the hunting for that reason, male lions are to big and slow to catch anything besides something slow, and male lions who live in more wooded areas are more likley to hunt for themselves
there are often only 2 adult male lions in a pride and many females with cubs of either gender
lions r very defensive and protective of their prides and usually males will not tolerate outside males and the females will not tolerate outside females
male lions are expelled or leave on their own wen they mature
the new male leaders, after they "dethrone" the past leader, will often kill the remaining cubs

and there is my detailed definition :)

(verb) Running your fingers through your partner's hair durning vigorous making out causing a drastic increase in hair volume; thus causing the hair to take on the appearance of a lion's mane.

1- A big feline, not as big as the tiger, but much stronger. It used to inhabit a large part of the middle east, india and even europe. More than just a big cat, it's really sociable, they live in prides and share the game. The lioness, almost always is the hunter, the male lion is known as a lazy bastard but in fact he deserves to be treated as a king, since he is the guardian of the family. They live in jungles, too (the asiatic lion in india).

2- Someone showing bravery, masculinity or both

The notion that any adage or proverb will become instantly improved if you substitute one of the original words with "lion," as created by J. Jacques in his web comic, Questionable Content.

it is a cat, example of when you might use this word

A lion is when you insert your penis in the middle of a paper plate or leaf. This looks like a mane, in the effect that it resembles a lion. If you whip that shit out on a girl, she won't be able to help but try and tame that beast.