deo gratias means thanks be to God
"Let us say thanks to God"
"Deo Dicamus Gratias" is Latin for literally "We may say thanks to God" though it is better translated "That me may give thanks to God!" or "Give thanks to God!" This particular line originates from...
If you mean Hallelujia (if that's how you spell it) I think it is like, YAY!
Alleluia is a Greek version of Hallelujah, Hebrew for "praise the Lord".