This is the 83rd most frequent Turkish word.
su
Water.
Here, 'su' is used as a common noun referring to water.
Bardakta temiz su var.
There is clean water in the glass.
'Su' is used in a declined form 'suyu' indicating a specific object.
Suyu bitirdim, yenisini alabilir miyim?
I finished the water, can I get a new one?
The word 'su' describes a substance that is essential for survival.