Snowed-Under common English idioms

What does snowed under mean?
Idiom: Snowed under.

Meaning: Overwhelmed by a lot of work; extremely busy with work.


He had applied for a grant but at the time the City Council was snowed under with applications.
Airlines are already snowed under by regulations.
We are certainly snowed under, it is a huge project.

The meaning of the idiom snowed under.