Slackadaisical

Usually it is when a co-worker is making a mess of things, you know it, and your own workload is increasing in a direct inverse ratio to his slackadaisical ways.

Source: wiktionary

But they're worlds apart from the bleary, slackadaisical euphoria of Happy Mondays.

Source: wiktionary

Ah, the simple and majestic bean bag; this stalwart of youth, this icon of a slackadaisical generation, like a sceptered isle of laziness awash in the mellow fruitfulness of simpler days.

Source: wiktionary