The word(s) "worst" appears 22 time(s) in 22 verse(s) in Quran in Saheeh International translation.

(1) And [recall] when We saved your forefathers from the people of Pharaoh, who afflicted you with the worst torment, slaughtering your [newborn] sons and keeping your females alive. And in that was a great trial from your Lord.

(2) Or lest you say, "If only the Scripture had been revealed to us, we would have been better guided than they." So there has [now] come to you a clear evidence from your Lord and a guidance and mercy. Then who is more unjust than one who denies the verses of Allah and turns away from them? We will recompense those who turn away from Our verses with the worst of punishment for their having turned away.

(3) And [recall, O Children of Israel], when We saved you from the people of Pharaoh, [who were] afflicting you with the worst torment - killing your sons and keeping your women alive. And in that was a great trial from your Lord.

(4) And [mention] when your Lord declared that He would surely [continue to] send upon them until the Day of Resurrection those who would afflict them with the worst torment. Indeed, your Lord is swift in penalty; but indeed, He is Forgiving and Merciful.

(5) Indeed, the worst of living creatures in the sight of Allah are the deaf and dumb who do not use reason.

(6) Indeed, the worst of living creatures in the sight of Allah are those who have disbelieved, and they will not [ever] believe -

(7) For those who have responded to their Lord is the best [reward], but those who did not respond to Him - if they had all that is in the earth entirely and the like of it with it, they would [attempt to] ransom themselves thereby. Those will have the worst account, and their refuge is Hell, and wretched is the resting place.

(8) But those who break the covenant of Allah after contracting it and sever that which Allah has ordered to be joined and spread corruption on earth - for them is the curse, and they will have the worst home.

(9) And [recall, O Children of Israel], when Moses said to His people, "Remember the favor of Allah upon you when He saved you from the people of Pharaoh, who were afflicting you with the worst torment and were slaughtering your [newborn] sons and keeping your females alive. And in that was a great trial from your Lord.

(10) Then We will surely extract from every sect those of them who were worst against the Most Merciful in insolence.