The small umbrellas that are attached to the main umbrella.
Subumbrellas are cute and useful for protecting from the sun or rain.
Examples:
The big umbrella has many subumbrellas attached to it.
I like the colorful subumbrellas on this umbrella.
The subumbrellas protect me from the sun.
The subumbrellas look like little hats on the big umbrella.
There are so many subumbrellas, it looks like a rainbow!
I want a big umbrella with lots of subumbrellas.