A meaningful sentence is a sentence that has clues that explain the meaning of a word.
Example of non-meaningful sentence: I was scared when I saw the large octupus. (This is not meaningful because if you didn't know what an octopus was, you couldn't tell by the sentence.)
Example of meaningful sentence: While swimming in the ocean, I was frightened by the eight-armed octupus when it sprayed its "ink." (Ocean is a clue, eight arms might mean a spider but ocean tells you it is a squid or octupus, and ink gives you the final clue.)
Example of non-meaningful sentence: My brother has a timpani which he loves.
Example of meaningful: My brother has many drums but likes the the sound of the timpani with its large brass kettle which resonate the sound.
And now an example of a meaningful sentence with a word you are not probably familiar with:
Whenever I come home, my Sloughi is so happy to see me that he wags his tail, jumps on me, and licks my face.
You can tell that a Sloughi is a type of dog.
Bev (a teacher and mom to David)