snowball (n.) Look up snowball at Dictionary.com
c.1400, from snow (n.) + ball (n.1). Similar formation in West Frisian sniebal, Middle Dutch sneubal, German Schneeball, Danish snebold. Expression snowball's chance (in hell) "no chance" is recorded by 1910.
snowball (v.) Look up snowball at Dictionary.com
"to make snowballs," 1680s, from snowball (n.); sense of "to throw snowballs at" (someone) is from 1850. Meaning "to increase rapidly" is attested from 1929, though the image of a snowball increasing in size as it rolls along had been used since at least 1613, and a noun sense of "a pyramid scheme" is attested from 1892. Related: Snowballed; snowballing.