This is the 1962nd most frequent Turkish word.
not
"Grade" or "note."
In this sentence, the word 'not' refers to a written note or remark, commonly used to denote a personal or academic memo.
Notumu deftere yazdım.
I wrote my note in the notebook.
Here, 'not' is used to mean a grade or score obtained in an academic evaluation.
Matematik sınavından yüksek not aldım.
I received a high grade on the math exam.
In this usage, 'not' refers to the act of making note or taking notice of something, conjugated as a verb in the sense of actively marking.