Generic name for any useless consumer gadget of the sort frequently sold on late-night infomercials. Commonly sold together with a tomato musher. Originally from the comic strip Bloom County. Opus was powerless to resist late-night TV hucksters and ended up with a living room full of turnip twaddlers.
"We'll sell you this amazing turnip twaddler for $29.95! But wait! There's more! We'll throw in this tomato musher ABSOLUTELY FREE! Now how much would you pay?"
Much the same as "living shit", "the bejesus", or "the devil"; for example, when you're beating the living shit out of something.
Andrew went on the rampage at work this morning when the copier spit toner all over him -- he literally beat the living tweedle out of the poor, defenseless, helpless copy machine!
Topher was so fond of his new R/C piloting skills; he flew the living tweedle out of his Cessna 182 R/C airplane at the park over the weekend.