Used informally among friends or in relaxed settings; not suitable in formal situations.

Colloquial Usage

Carries a strong negative judgment, often offending the person described.

Negative Connotation

Emphasizes extreme laziness, more than just being occasionally lazy.

Be accurate when using it; don't describe someone as 'bone idle' for a minor laziness instance.

It's an expression; doesn't mean the person's bones are literally idle.

Most familiar in the UK; learners should know it's less common in other English-speaking regions.