This is the 830th most frequent Turkish word.
suyu
"The water" or "its water" (possessive form of "su").
The word 'suyu' refers to the possessive form of 'water' pertaining to the pot.
Bu saksının suyu çok azaldı.
The water of this pot has decreased a lot.
Here, 'suyunu' represents the specific juice of the orange in possessive form, used as an object.
Portakalın taze sıkılmış suyunu tercih ederim.
I prefer fresh-squeezed orange juice.
In this case, 'suyu' is used in the accusative case indicating 'water' as the specific object of drinking.