Meaning : A lightweight handheld collapsible canopy.
Meaning : A formation of military planes maintained over ground operations or targets.
Example :
An air umbrella over England.
Meaning : Having the function of uniting a group of similar things.
Example :
The Democratic Party is an umbrella for many liberal groups.
Under the umbrella of capitalism.
Meaning : Covering or applying simultaneously to a number of similar items or elements or groups.
Example :
An umbrella organization.
Umbrella insurance coverage.