[hwam-oh, wam-oh] 
Informal.| 1. | (used to indicate the sound of a blow, collision, falling object, etc.). |
| 2. | immense energy; vigor: a movie with plenty of whammo to please the kids. |
| 3. | characterized by such a strong effect: a show with a whammo ending. |
| 4. | wham. |
[hwam, wam] noun, interjection, verb, whammed, wham⋅ming, adverb | 1. | a loud sound produced by an explosion or sharp impact: the wham of a pile driver. |
| 2. | a forcible impact. |
| 3. | (used as an exclamation suggestive of a loud slam, blow, or the like). |
| 4. | to hit or make a forcible impact, esp. one producing a loud sound: The boat whammed into the dock. He whammed the door shut. |
| 5. | Also, whammo. abruptly; with startling suddenness: The car ran wham up against the building. |
| wham·mo (hwām'ō, wām'ō) interj. Slang Used to indicate the startling abruptness of a sound, action, or event: "The alarm goes off and—whammo!—we're all at our assigned stations" (Meg Greenfield). [Alteration of wham.] |