The Collaborative International Dictionary
Snowball \Snow"ball`\, v. t. [imp. & p. p. Snowballed; p. pr. & vb. n. Snowballing.] To pelt with snowballs; to throw snowballs at.
Wiktionary
vb. (en-past of: snowball)
Usage examples of "snowballed".
Any man so unwise as to walk alone by day was apt to be set upon and snowballed and, if caught, thrashed—be he even skald or mighty hunter.
Things just snowballed, and before long I was so busy brokering transfers of military material from one point to another that it was damned seldom I could make the time to perform what was my primary job for my firm.
The sounds snowballed into a terrific roaring, and Raed moved one hand off the vibrating railing onto his belt, fingered the ripcord, and looked up in anticipation–to his astonishment, some civilians who had made it down from the landing above were squeezing between the firemen.
However, it snowballed and among other places from which high ranking people have enrolled are the National Data Banks.