The word(s) "plain" appears 101 time(s) in 98 verse(s) in Quran in Mohsin Khan translation.

(81) "Only this has been revealed to me, that I am a plain warner."

(82) Is he whose breast Allah has opened to Islam, so that he is in light from His Lord (as he who is a non-Muslim)? So woe to those whose hearts are hardened against remembrance of Allah! They are in plain error!

(83) A Book whereof the Verses are explained in detail - a Qur'an in Arabic for people who know.

(84) And if We had sent this as a Qur'an in a foreign language (other than Arabic), they would have said: "Why are not its verses explained in detail (in our language)? What! (A Book) not in Arabic and (the Messenger) an Arab?" Say: "It is for those who believe, a guide and a healing. And as for those who disbelieve, there is heaviness (deafness) in their ears, and it (the Qur'an) is blindness for them. They are those who are called from a place far away (so they neither listen nor understand)."

(85) And let not Shaitan (Satan) hinder you (from the right religion, i.e. Islamic Monotheism). Verily, he (Satan) to you is a plain enemy.

(86) How can there be for them an admonition (at the time when the torment has reached them), when a Messenger explaining things clearly has already come to them.

(87) And granted them signs in which there was a plain trial.

(88) Then We have put you (O Muhammad صلى الله عليه و سلم) on a (plain) way of (Our) commandment [like the one which We commanded Our Messengers before you (i.e. legal ways and laws of the Islamic Monotheism)]. So follow you that (Islamic Monotheism and its laws), and follow not the desires of those who know not. (Tafsir At-Tabari).

(89) And when Our Clear Verses are recited to them, the disbelievers say of the truth (this Qur'an) when it reaches them: "This is plain magic!"

(90) Say (O Muhammad صلى الله عليه وسلم): "I am not a new thing among the Messengers (of Allah i.e. I am not the first Messenger) nor do I know what will be done with me or with you. I only follow that which is revealed to me, and I am but a plain warner."