x-ing

noun pl. X's, x's

1. the twenty-fourth letter of the English alphabet: from a western form of the Greek alphabet
2. any of the speech sounds that this letter represents, as, in English, the (ks) of lax, (gz) of exact, (ks̸h) of anxious, (gz̸h) of luxurious, or (z) of xylophone
3. a type or impression for x or X
4. the twenty-fourth in a sequence or group
5. an object shaped like

adjective

1. of x or X
2. twenty-fourth in a sequence or group
3. shaped like