The word(s) "mightier" appears 4 time(s) in 3 verse(s) in Quran in Mohsin Khan translation.

(1) Like those before you: they were mightier than you in power, and more abundant in wealth and children. They had enjoyed their portion (awhile), so enjoy your portion (awhile) as those before you enjoyed their portion (awhile); and you indulged in play and pastime (and in telling lies against Allah and His Messenger Muhammad صلى الله عليه وسلم) as they indulged in play and pastime. Such are they whose deeds are in vain in this world and in the Hereafter. Such are they who are the losers.

(2) Have they not travelled through the earth and seen what was the end of those before them? They were more in number than them and mightier in strength, and in the traces (they have left behind them) in the land; yet all that they used to earn availed them not.

(3) As for 'Ad, they were arrogant in the land without right, and they said: "Who is mightier than us in strength?" See they not that Allah, Who created them was mightier in strength than them. And they used to deny Our Ayat (proofs, evidence, verses, lessons, revelations, etc.)!