pseudo-violently high-powered action performed abruptly.
With one big wallop, the Gremlin's hairy bicep powered a fling that sent the record-breaking pumpkin onto it's endoatmospheric trajectory across the province.
An exclamation word, not a noun or verb etc. It is a word that is shouted in excitement. Often times when words just can not describe your true elation. Wallop is occasionally a substitute when shouting infidelities is not needed or appropriate. Mostly used in Canada.
Wallop: Old(ish) English: The strongest ale in the tavern. (I got it from a pack of cards of old English expression. But I've never found anyone in England (and I've spent a lot of time there) or in America that's ever heard of it. So I'm trying to get it into circulation so these barmaids know what I'm talking about and I don't have to explain myself. But now I try to avoid saying, "Don't you know your own damn language?!" 'cuz then I usually have to find another pub.)