O vs water

O and water both are nouns.

Word	Noun	Adjective	Verb	Adverb
O	Yes	No	No	No
water	Yes	No	Yes	No

O (noun)	water (noun)
the blood group whose red cells carry neither the A nor B antigens	a facility that provides a source of water
the 15th letter of the Roman alphabet	a liquid necessary for the life of most animals and plants
a nonmetallic bivalent element that is normally a colorless odorless tasteless nonflammable diatomic gas; constitutes 21 percent of the atmosphere by volume; the most abundant element in the earth's crust	the part of the earth's surface covered with water (such as a river or lake or ocean)
	binary compound that occurs at room temperature as a clear colorless odorless tasteless liquid; freezes into ice below 0 degrees centigrade and boils above 100 degrees centigrade; widely used as a solvent
	liquid excretory product
	once thought to be one of four elements composing the universe (Empedocles), associated with the humour phlegm

O (verb)	water (verb)
	secrete or form water, as tears or saliva
	supply with water, as with channels or ditches or streams
	fill with tears
	provide with water