Adjective
Physically very solid; very difficult to move.
(figuratively) Very strong and dependable.
Source: en.wiktionary.orgWashington's character was rock solid. He came to stand for the new nation and its republican virtues, which was why he became our first President by unanimous choice. Stephen Ambrose
The first 3 years the focus would be entirely on [...] building a rock solid infrastructure. Matt Mullenweg
Spirituality and faith are at the core of who I am. I was born to deeply religious parents who were able to give me that rock solid foundation in the church and in my faith which really has served me so well. Condoleezza Rice
I want you and the people of Israel to know a few things that have not and will not change. The United States stands firmly with Israel, and we have a rock solid commitment to the security of Israel and to the security of its citizens. Leon Panetta
Parents walk a fine line between discipline and grace - values have to hold even when circumstances change or call for compromise or compassion. It's the ultimate challenge to be both firm and fluid, soft and strong, yielding yet rock solid. Kristin Armstrong