When things synergize, they work together to make a better result than they could alone.
Synergizing is usually a very good thing. It means things are working together in a strong and smart way.
Examples:
The team synergized to win the game.
The colors of the painting synergized to make it beautiful.
The two companies synergized to make a new product.
The animals synergized to escape from the zoo!
The superhero team synergized their powers to defeat the villain.
The music and the dancing synergized to make a great show.