A straightforward noun for a person who habitually avoids work or effort. Can be used teasingly or as mild criticism.
My younger brother is a lazy person and always puts off his homework.
彼は怠け者だから、朝早く起きられない。
He's a lazybones, so he can't get up early in the morning.
He's a total slacker who sleeps all day on his days off.
If you don't do your homework, everyone will call you a lazybones.
Even though he's such a lazybones, his grades are surprisingly good.
Rarely used kanji form; 懶 is not a standard jōyō kanji.