down below—
1. in a lower part of a building, ship, etc.:
- Someone was with me and we proceeded to open the hatch to the flooded compartment down below.
2. under the ocean or sea:
- Wherever there’s a lot of seaweed at the surface, you will probably find some sort of big fish down below.
down under—(coll.) said of Australia or New Zealand:
- The last time I was Down Under was ten years ago. It was my second visit to Australia.
See also: down here / here below.