Which letter of the English Alphabet is used the least?

I’m not sure that the American Alphabet would have same outcome as the suffix -ise/ideation is normally changed to ize/ization.

Que is at the end of numerous words, so Z seems to lose out.

Jazzy is probably the hardest word to solve in hangman. has 3 of the least popular letters. Never lose. Y.N.W.A. JFT96

Qi is another one