HOW TO UNDERSTAND THIS?

Rock solid means it is a sure thing, strong and unchangeable.

Example:
His advice was rock solid, he was correct about the solution to the problem.

Solid as a rock. Immovable.

Nothing to do with rock music, by the way.

Well, no direct connection to rock music anyway, but here's an old rock tune that might shed some light on the meaning of this, Chinahorizon.

Solid as a Rock

Ashford & Simpson

[ Simpson: ]
And for love’s sake, {And for love's sake,}
Each mistake, {Each mistake,}
Oh, you forgave. {Oh, you forgave.}
And soon both of us, {And soon both of us,}
Learned to trust, {Learned to trust,}
Not run away. {Run away, run away.}

[ Ashford: ] It was no time to play.
[ Simpson: ] We built it up. {Built it up.}
[ Ashford: ] And built it up.
[ Simpson: ] And built it up. {Built it up.}

[ Backup: ] And now it’s solid. {Solid, solid.}
Solid as a rock. That’s what this love is.
[ Simpson: ] That’s what we’ve got. Oh, mmmm.

[ Backup: ] Solid.
[ Ashford: ] Hah.
[ Backup: ] Solid as a rock. And nothing’s changed it.
[ Ashford: ] Woot. The thrill is still,
[ All: ] Ha-ha-ha-ha-ha-ha-ha-hot.

[ Ashford: ] Oh-oh-oh-oh, hah.
You didn’t turn away when the sky went gray.
Somehow we managed. We had to stick together.

[ Backup: ] Ooo-ooo-ooo-ooo.

[ Ashford: ]
You didn’t bat an eye when I made you cry.
We knew down the line, we would make it better.

[ Backup: ] Ooo-ooo-ooo-ooo.

[ Simpson: ]
And for love’s sake, each mistake, oh, you forgave.
And soon both of us learned to trust, not run away.

[ Ashford: ] It was no time to play.
[ Simpson: ] We built it up.
[ Ashford: ] And built it up.
[ Simpson: ] And built it up.
[ Backup: ] And now it’s solid. Solid as a rock.
[ Ashford: ] Woot.
[ Backup: ] That’s what this love is.
[ Ashford: ] Ahhhh. That’s what we’ve got.
[ Simpson: ] Oh-oh-oh.
[ Ashford: ] Yes it is.

[ Backup: ] Solid. Solid as a rock. And nothing’s changed it.
[ Find more Lyrics at www.mp3lyrics.org/GqVm ]
[ Simpson: ] Aahhh. The thrill is still,
[ All: ] Ha-ha-ha-ha-ha-ha-ha-hot.

[ Ashford: ] Oh-oh-oh-oh, hah.
Gone with the wind, another friend,
Got in between, and tried to separate us.

[ Backup: ] Ooo-ooo-ooo-ooo.

[ Ashford: ]
Oh, knock-knock on wood, you understood.
Love was so new. We did what we had to.

[ Backup: ] Ooo-ooo-ooo-ooo.

[ Simpson: ]
And with that feelin', we were willin' to take a chance.
So against all odds, we made a start. We got serious.

[ Ashford: ] Woot. This wouldn’t turn to dust.
[ Simpson: ] We built it up.
[ Ashford: ] And built it up.
[ Simpson: ] And built it up.

[ Backup: ] And now it’s solid.
[ Ashford: ] Woot.
[ Backup: ] Solid as a rock. That’s what this love is.
[ Simpson: ] Ohhh. That’s what we’ve got, oh.
[ Ashford: ] Ohhhh-ohhh.

[ Backup: ] Solid.
[ Ashford: ] Yes it is.
[ Backup: ] Solid as a rock.
[ Ashford: ] Ahhhh.
[ Backup: ] And nothing’s changed it.
[ Ashford: ] Woot. The thrill is still,
[ All: ] Ha-ha-ha-ha-ha-ha-ha-hot.

[ Backup: ] Solid.
[ Ashford: ] Hah.
[ Backup: ] Solid as a rock.
[ Ashford: ] You know it.
[ Simpson: ] Well.
[ Ashford: ] You know it, baby.

[ Backup: ] Solid. Solid as a rock.
[ Ashford: ] Lovin’ me, lovin’ me, ah.

[ Backup: ] Solid.
[ Ashford: ] Don’t leave me, baby. Ah!
[ Backup: ] Solid as a rock.
[ Simpson: ] Well, well, well, well, ahhh!

[ Backup: ] Solid. Solid as a rock.
[ Ashford: ] Every day it gets sweeter, now.
[ Simpson: ] Ooo.

[ Backup: ] Solid.
[ Simpson: ] You know I like it.
[ Backup: ] Solid as a rock.
[ Ashford: ] Good, good.
[ Simpson: ] well.
[ Ashford: ] It’s good, good, good.
[ Backup: ] Solid solid, solid, solid, solid, solid...

Thank u for you help. I got it.

TNANK U VERY MUCH.

What does "Woot" mean?

JTT, THANKS FOR SHARING SUCH TUNE.

Beats me, EBrown.