The word(s) "plain" appears 70 time(s) in 69 verse(s) in Quran in Abdullah Yusuf Ali translation.

(41) "He will leave them as plains smooth and level;

(42) Thus have We sent this down - an arabic Qur'an - and explained therein in detail some of the warnings, in order that they may fear Allah, or that it may cause their remembrance (of Him).

(43) And Allah makes the Signs plain to you: for Allah is full of knowledge and wisdom.

(44) So (Moses) threw his rod, and behold, it was a serpent, plain (for all to see)!

(45) "I am sent only to warn plainly in public."

(46) Verily this Qur'an doth explain to the Children of Israel most of the matters in which they disagree.

(47) He does propound to you a similitude from your own (experience): do ye have partners among those whom your right hands possess, to share as equals in the wealth We have bestowed on you? Do ye fear them as ye fear each other? Thus do we explain the Signs in detail to a people that understand.

(48) Then, when We decreed (Solomon's) death, nothing showed them his death except a little worm of the earth, which kept (slowly) gnawing away at his staff: so when he fell down, the Jinns saw plainly that if they had known the unseen, they would not have tarried in the humiliating Penalty (of their Task).

(49) 'Only this has been revealed to me: that I am to give warning plainly and publicly."

(50) A Book, whereof the verses are explained in detail;- a Qur'an in Arabic, for people who understand;-