This is the 9th most frequent Marathi word.
एक
"One."
The word 'एक' acts as a numeral, meaning 'one'.
मी एक पुस्तक वाचतो.
I read one book.
The word 'एक' emphasizes the singularity of the 'argument' being pointed out.
त्याच्याकडे एक चांगले युक्तिवाद आहे.
He has a good argument.
The word 'एक' contributes to an adverbial phrase, indicating 'one time' or 'once'.