Douglas Harper's Etymology Dictionary
"ineffectual," 1932; "Dictionary of American Slang" suggests it is perhaps a humorous mispronunciation of haphazard.
Wiktionary
a. poorly or incompetently done alt. poorly or incompetently done
Usage examples of "half-assed".
Leslie already had that half-assed comparison of the birdcage to some sort of sacred site stuck in his mind when he and Charlie soared through the bars, leaving the rest of the EVA team behind.
He had been through the entire list of the usuals, from Satanists all the way to half-assed dopeheads who thought they could bring on a better world by chopping the heads off calves and goats.
The island laws were administered through some half-assed tribunal called a subprefecture on St.
Maybe Dylan could concoct a half-assed story to explain what he and his brother were doing here when they were supposed to be on the road in New Mexico, but he didn't have the talent for deception or the time to craft a story to explain the gateway, the motel bathroom here on the hill, and Jilly peering cluelessly out at them as though she were Alice unsuccessfully attempting to scope the nature of the enchanted realm on the far side of the looking glass.
I made myself a fried-egg sandwich for lunch, changed my jeans, brushed my hair into a half-assed ponytail, and plastered a ton of concealer over my pimple.
As Peter hadn't even formulated what he envisioned of T&T to tell Johnny, he certainly didn't want to muddy that idea with another half-assed concept, like breaking Tithonus free of the Patroclus group and moving it to an orbit around Callisto and using that as his place to stand.
I told him twice about that van, but he pooh-poohed the idea, said if he stopped to track down every half-assed theory the John Q.
I told him twice about that van, but he pooh-poohed the idea, said if he stopped to track down every half-assed theory the John Q. Public volunteered, he wouldn't get anything else done.
I spotted a space halfway between my apartment and the restaurant and then did a half-assed job of parallel parking.
Nikki said, attempting to remain calm, although she was completely unthrilled to discover her daughter sitting on a bed in a hotel room with some half-assed actor.