A flat topped flower cluster is called a corymb or a cyme.
A flat topped mud brick tomb is called a mastaba.
ziggurat
Cyme
Unusual flat-topped seamounts in the ocean are called Guyots. Guyots are submerged volcanic mountains with a flat top that has been eroded by waves and currents over time.
A flat-topped mountain is called a plateau. Plateaus are elevated landforms with a relatively flat top surface that are often formed by the erosion of surrounding land.
We apply the term mesa to a flat-topped mountain.
plateau
the pyramid of giza.
mesa's
Butte
Small flat-topped hills found in the Southwest are called mesas. They are geological formations with steep sides and a relatively flat top. Mesas are commonly found in arid and semiarid regions.
it means either a flat topped submarine mountain or a flat topped seamount.