Which sound device is illustrated by the invented word snicker-snack in these lines from "jabberwocky"? one, two! one, two! and through and through the vorpal blade went snicker-snack!

In the poem "Jabberwocky" the word snicker-snack uses the literary sound device alliteration. Alliteration is the repetition of beginning consonant sounds in words. For example: Peter Piper picked a peck of pickled peppers. It is also used as a sort of Onomatopoeia, but Carroll made up many of the words inside of the poem.