Why do we call H2O water instead of hydrogen oxide

When we call other compounds such as CO2, carbon dioxide? Is it just to make it easier since it's so common and apparent in our lives?

The word 'water' goes through many, many languages, as well as through ages of history. These words for water existed before chemical formulas were formed, so easily discernible substances like water were simply given names.

Saltpeter is another example because there was no chemical formula for it several hundred years ago, but rather just a name that made it distinctive. Saltpeter is essentially just potassium nitrate, but since there was no chemical formula, periodic table, etc. for it hundreds or even thousands of years ago, people were satisfied with simply giving it a name.

But yes, saying water is much easier, so that has a little bit to do with why we call H2O, 'water', in these contemporary times. Also, we need a well-defined system to name our chemical compounds, seeing that memorizing an endless list of names can become an arduous and difficult task.

Water is a name that predates the use of the words hydrogen and oxygen. It has been kept for historical reasons. Another example would be using ammonia rather than nitrogen trihydride.

BTW, other possibilities for alternate names for water would be hydrogen hydroxide and dihydrogen monoxide.

The liquid we call water was named many years before its composition was know and for a long time it was the only oxide of hydrogen known. The other oxide of H is hydrogen peroxide to distinguish it from the monoxide (H2O). The per in peroxide means more oxygen than in the usual oxide.

"Hey, dude, can you pour me a glass of that dihydrogen oxide" or "Drink 8 cups of dihydrogen oxide a day!" just doesn't have the same ring to it :)
Also in your question it should say *di*hydrogen oxide since there's 2 hydrogens

All opinion, but I think that it should be dihydrogen oxide but was given a primary name due to it's abundance and need for human survival before "chemistry" went about naming things.

2 hydrogen molecules 1 oxygen molecule, making H20 or water. I don't see why we'd call it anything else.

Because we called it water before we found out what its molecular formula is.

Yep. Not everyone knows chemistry.

H2O is a water. It is what we drink. Why speak so "chemically" when there're basic word for it?

coz water is a smaller word