This is the 9042nd most frequent Turkish word.
tersi
The opposite; the reverse.
The word 'tersi' refers to the reversal or the opposite aspect of something in this context.
Olayların tersini düşündüm.
I thought about the reversal of events.
Here, 'tersi' is used to describe the opposite or back side of a physical object.
Bu kapının tersini boyamışsın.
You painted the reverse side of this door.
In this sentence, 'tersi' signifies the contrary action or choice in comparison to a given one.