A lazy person; lazy/idle (colloquial). Used as a noun or na-adjective to describe someone who loafs or shirks work.
休日は家でぐうたらしてテレビばかり見ていた。
I lazed around at home on my day off and watched TV all day.
彼はぐうたらな性格で、家事を全然手伝わない。
He's lazy by nature and never helps with the housework.
母に『ぐうたらするな』と叱られた。
My mother scolded me, 'Don't be lazy.'