This is the 482nd most frequent Azerbaijani word.
deyən
"One who says" or "saying."
In this context, 'deyən' is a participle form derived from the verb 'demək' (to say), used to describe someone who says something specific.
O mənim bu barədə düşündüyümü deyən yeganə insandır.
He is the only person who says what I think about this.
Here, 'deyən' functions as a noun, referring to the person who said something.
Müəllim, burada səhv olmadığını deyənə inandım.
Teacher, I believed the one who said there was no mistake here.
In this sentence, 'deyən' conveys the action of saying, within a conditional or hypothetical structure.