The word(s) "sign" appears 351 time(s) in 320 verse(s) in Quran in Mohsin Khan translation.

(161) And indeed We showed him [Fir'aun (Pharaoh)] all Our Ayat (signs and evidence), but he denied and refused.

(162) They said: "We prefer you not over what have come to us of the clear signs and to Him (Allah) Who created us. So decree whatever you desire to decree, for you can only decree (regarding) this life of the world.

(163) (Allah) will say: "Like this: Our Ayat (proofs, evidence, verses, lessons, signs, revelations, etc.) came unto you, but you disregarded them (i.e. you left them, did not think deeply in them, and you turned away from them), and so this Day, you will be neglected (in the Hell-fire, away from Allah's Mercy)."

(164) And thus do We requite him who transgresses beyond bounds [i.e. commits the great sins and disobeys his Lord (Allah) and believes not in His Messengers, and His revealed Books, like this Qur'an], and believes not in the Ayat (proofs, evidence, verses, lessons, signs, revelations, etc.) of his Lord; and the torment of the Hereafter is far more severe and more lasting.

(165) Is it not a guidance for them (to know) how many generations We have destroyed before them, in whose dwellings they walk? Verily, in this are signs indeed for men of understanding.

(166) They say: "Why does he not bring us a sign (proof) from his Lord?" Has there not come to them the proof of that which is (written) in the former papers [Scriptures, i.e. the Taurat (Torah), and the Injeel (Gospel), about the coming of the Prophet Muhammad صلى الله عليه وسلم]?

(167) And if We had destroyed them with a torment before this (i.e. Messenger Muhammad صلى الله عليه وسلم and the Qur'an), they would surely have said: "Our Lord! If only You had sent us a Messenger, we should certainly have followed Your Ayat (proofs, evidence, verses, lessons, signs, revelations, etc.), before we were humiliated and disgraced."

(168) Nay, they say: "These (revelations of the Qur'an which are revealed to Muhammad صلى الله عليه وسلم) are mixed up false dreams! Nay, he has invented them! - Nay, he is a poet! Let him then bring us an Ayah (sign as a proof) like the ones (Prophets) the former were sent (with)!"

(169) Not one of the towns (populations), of those which We destroyed, believed before them (though We sent them signs): will they then believe?

(170) And We have made the heaven a roof, safe and well guarded. Yet they turn away from its signs (i.e. sun, moon, winds, clouds, etc.).