The word(s) "unbelievers" appears 175 time(s) in 158 verse(s) in Quran in Abdullah Yusuf Ali translation.

(71) When the unbelievers see thee, they treat thee not except with ridicule. "Is this," (they say), "the one who talks of your gods?" and they blaspheme at the mention of (Allah) Most Gracious!

(72) If only the unbelievers knew (the time) when they will not be able to ward off the fire from their faces, nor yet from their backs, and (when) no help can reach them!

(73) Then will the true promise draw nigh (of fulfilment): then behold! the eyes of the unbelievers will fixedly stare in horror: "Ah! Woe to us! we were indeed heedless of this; nay, we truly did wrong!"

(74) Verily ye, (unbelievers), and the (false) gods that ye worship besides Allah, are (but) fuel for Hell! to it will ye (surely) come!

(75) And the Companions of the Madyan People; and Moses was rejected (in the same way). But I granted respite to the unbelievers, and (only) after that did I punish them: but how (terrible) was my rejection (of them)!

(76) When Our Clear Signs are rehearsed to them, thou wilt notice a denial on the faces of the unbelievers! they nearly attack with violence those who rehearse Our Signs to them. Say, "Shall I tell you of something (far) worse than these Signs? It is the Fire (of Hell)! Allah has promised it to the unbelievers! and evil is that destination!"

(77) The chiefs of the unbelievers among his people said: "He is no more than a man like yourselves: his wish is to assert his superiority over you: if Allah had wished (to send messengers), He could have sent down angels; never did we hear such a thing (as he says), among our ancestors of old."

(78) If anyone invokes, besides Allah, Any other god, he has no authority therefor; and his reckoning will be only with his Lord! and verily the unbelievers will fail to win through!

(79) But the unbelievers,- their deeds are like a mirage in sandy deserts, which the man parched with thirst mistakes for water; until when he comes up to it, he finds it to be nothing: But he finds Allah (ever) with him, and Allah will pay him his account: and Allah is swift in taking account.

(80) Or (the unbelievers' state) is like the depths of darkness in a vast deep ocean, overwhelmed with billow topped by billow, topped by (dark) clouds: depths of darkness, one above another: if a man stretches out his hands, he can hardly see it! for any to whom Allah giveth not light, there is no light!