noun, na-adjective
Describes a person who habitually avoids work or effort; often used in a mildly scolding or self-deprecating way. Can also be used adjectivally with な.
彼はぐうたらで、一日中ソファに寝転がっている。
He's a lazybones, lying on the sofa all day.
ぐうたらな生活を改めたい。
I want to change my idle lifestyle.
Katakana variant used for emphasis or in casual writing.
怠け者 is a more standard and slightly formal term for a lazy person, while ぐうたら is colloquial and carries a stronger nuance of being habitually idle or good-for-nothing.
The origin is uncertain; it is a colloquial mimetic-like word that may have developed from the sound-symbolic reduplication pattern seen in other informal terms.