Semidomes are half of a dome shape, like half of a round roof or ceiling.
Semidomes are often used in architecture to make buildings look grand and impressive.
Examples:
The church has semidomes on its roof.
The palace has beautiful semidomes.
The semidomes are painted with colorful pictures.
The semidomes look like big smiles on the building.
The semidomes make the building look like a giant cake.
I like to look at the semidomes when I walk by the building.