From sneeuwbal +‎ effect, perhaps a calque.

• IPA^(key): /ˈsneːu̯.bɑl.ɛˌfɛkt/

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• Hyphenation: sneeuw‧bal‧ef‧fect

sneeuwbaleffect n (plural sneeuwbaleffecten, no diminutive)

1. snowball effect