Have you ever seen an eclipse? That's when the sun, earth or moon cross paths and cover each other up temporarily.
A solar eclipse happens when the moon blocks our view of the sun for a bit. A lunar eclipse happens when the moon is on one side of the earth and the sun directly opposite, so the moon disappears. A TV eclipse, perhaps the most serious of all, is when your dad walks in at the most crucial part of the movie and blocks your view of the TV while he lectures about taking out the trash.