be (as) solid as a rock

To be stable, sturdy, and reliable. They've been married for 50 years, so their relationship has to be solid as a rock. That table must be as solid as a rock to withstand the ceiling collapse with hardly a scratch.

Common Names:

Name	Pronounced	Usage
Alfonsina	-	Italian
BÉLa	BAY-law	Hungarian
Birgitta	bir-YIT-tah (Swedish), bir-GIT-tah (Swedish), BEER-geet-tah (Finnish)	Swedish, Norwegian, Danish, Icelandic, Finnish
Prosperus	-	Late Roman
Stefano	ste-FAH-no	Italian
Mireille	mee-RAY	French