This is the 4935th most frequent Arabic word.
العالم
The world; the universe.
In this sentence, "العالم" means 'the world', referring to the Earth or the global environment.
العالم مكان واسع مليء بالمفاجآت.
The world is a vast place full of surprises.
Here, "العالم" again means 'the world', but its usage emphasizes a global context when describing renown or fame.
أنطوان أينشتاين هو أحد أشهر العلماء في العالم.
Albert Einstein is one of the most famous scientists in the world.
In this context, "العالم" means 'the scientist' when paired with a specialization ("الكيميائي" = the chemist).