This is the 2075th most frequent Turkish word.
çetin
Difficult; tough; challenging.
Here, 'çetin' means difficult, describing the challenging nature of the exam.
Çetin bir sınava girdik.
We took a difficult exam.
In this instance, 'çetin' conveys a sense of increasing difficulty or adversity in the context of evolving circumstances.
Olaylar çetinleşiyor, dikkatli olmalıyız.
Events are becoming tougher, we need to be cautious.
Here, 'Çetin' is a proper noun, a common male first name in Turkish, unrelated to its adjective meaning.