The word(s) "vainly" appears 3 time(s) in 3 verse(s) in Quran in Abdullah Yusuf Ali translation.

(1) Say: "Shall we indeed call on others besides Allah,- things that can do us neither good nor harm,- and turn on our heels after receiving guidance from Allah? - like one whom the evil ones have made into a fool, wandering bewildered through the earth, his friends calling, come to us', (vainly) guiding him to the path." Say: "Allah's guidance is the (only) guidance, and we have been directed to submit ourselves to the Lord of the worlds;-

(2) Such (was) Jesus the son of Mary: (it is) a statement of truth, about which they (vainly) dispute.

(3) Is he, then, to whom the evil of his conduct is made alluring, so that he looks upon it as good, (equal to one who is rightly guided)? For Allah leaves to stray whom He wills, and guides whom He wills. So let not thy soul go out in (vainly) sighing after them: for Allah knows well all that they do!