LAZIEST

Unwilling to do work or make an effort; disinclined to exertion.

Example: "Get out of bed, you lazy lout!"

Causing or characterised by idleness; relaxed or leisurely.

Example: "I love staying inside and reading on a lazy sunday."

Showing a lack of effort or care.

Example: "Lazy writing"

Sluggish; slow-moving.

Example: "We strolled along beside a lazy stream."

Lax:

(of a cattle brand) turned so that (the letter) is horizontal instead of vertical.

Employing lazy evaluation; not calculating results until they are immediately required.

Example: "A lazy algorithm"

Wicked; vicious.