This is the 6310th most frequent Turkish word.
üçüncüsü
"The third one."
The word 'üçüncüsü' is used to indicate the third position in a ranking or sequence in this context.
Bu yarışta üçüncüsü Ahmet oldu.
Ahmet became the third in this race.
Here, 'üçüncüsü' refers to the third floor as part of a sequential comparison.
Evin katları arasında üçüncüsü en geniş olanıydı.
Among the floors of the house, the third one was the largest.
In this sentence, 'üçüncüsü' indicates the third item among a group, showing a choice or comparison.