world

• planet or globe; particular part of earth; planet earth; universe, cosmos; humankind; general public, public as a whole; material realm (as opposed to the spiritual realm); a lot, very much
the world is the planet that we live on.
the world is also all the people who live on this planet.
world is used to describe someone or something that is one of the best or most important of its kind.
someone's world is their life, experiences, and the relationships they have with other people.
a particular world is a field of activity, and the people involved in it.
you can refer to a particular group of countries or a particular period in history as the western world, the arab world, the ancient world, and so on.
you can refer to the state of being alive as this world and to a state of existence after death as the next world.
you can refer to a group of living things as the animal world, the plant world, or the insect world.
you can refer to another planet as a world.
you can use in the world with superlatives to emphasize that the thing you are talking about is the most important, significant, or extreme of its kind.
the world over means throughout the world.
if someone has or wants the best of both worlds, they have or want all the benefits from two different situations, without the disadvantages.
if you think the world of someone or something, you admire them very much.
if something does you the world of good, it makes you feel better; an informal expression.
if there is a world of difference between two things, they are very different from each other.