The word(s) "conjecture" appears 8 time(s) in 7 verse(s) in Quran in Mohsin Khan translation.

(1) And because of their saying (in boast), "We killed Messiah 'Îsa (Jesus), son of Maryam (Mary), the Messenger of Allah," - but they killed him not, nor crucified him, but it appeared so to them [the resemblance of 'Îsa (Jesus) was put over another man (and they killed that man)], and those who differ therein are full of doubts. They have no (certain) knowledge, they follow nothing but conjecture. For surely; they killed him not [i.e. 'Îsa (Jesus), son of Maryam (Mary) عليهما السلام]:

(2) And if you obey most of those on the earth, they will mislead you far away from Allah's Path. They follow nothing but conjectures, and they do nothing but lie.

(3) And most of them follow nothing but conjecture. Certainly, conjecture can be of no avail against the truth. Surely, Allah is All-Aware of what they do.

(4) No doubt! Verily, to Allah belongs whosoever is in the heavens and whosoever is in the earth. And those who worship and invoke others besides Allah, in fact they follow not (Allah's so-called) partners, they follow only a conjecture and they only invent lies.

(5) Indeed they did disbelieve (in the Oneness of Allah, Islam, the Qur'an and Muhammad صلى الله عليه وسلم) before (in this world), and they (used to) conjecture about the Unseen [i.e. the Hereafter, Hell, Paradise, Resurrection and the Promise of Allah (by saying) all that is untrue], from a far place.

(6) And they say: "There is nothing but our life of this world, we die and we live and nothing destroys us except Ad-Dahr (time). And they have no knowledge of it: they only conjecture.

(7) And when it was said: "Verily, Allah's Promise is the truth, and there is no doubt about the coming of the Hour," you said: "We know not what is the Hour: we do not think it but as a conjecture, and we have no firm convincing belief (therein)."