That's solid.
That's solid.
That's solid" means something is reliable, dependable, or well-made. Imagine a business deal that is foolproof or advice that's always spot-on. When you say "that's solid," you are giving a firm nod of approval.
That's solid, man. His advice really holds up.
That's reliable, man. His advice truly stands.
Look at that car, now that’s solid!
Look at that car, now that’s reliable!
You always have great ideas, that's solid thinking right there.
You always have great ideas, that’s reliable thinking right there.