Which word ends with ff?

The correct answer is: Sniff

The most frequent double letter combinations are ee, ll, ss, oo, tt, ff, rr, pp, nn and cc. The double letters that occur most commonly at the end of words are ee, ll, ss, and ff. There is two words hot and sniff. Only the word 'sniff' has double letter. So, the word 'sniff' ends with ff.