having the function of uniting a group of similar things; "the Democratic Party is an umbrella for many liberal groups"; "under the umbrella of capitalism"
a formation of military planes maintained over ground operations or targets; "an air umbrella over England"
a lightweight handheld collapsible canopy
covering or applying simultaneously to a number of similar items or elements or groups; "an umbrella organization"; "umbrella insurance coverage"
a murderer (especially one who kills a prominent political figure) who kills by a treacherous surprise attack and often is hired to do the deed; "his assassins were hunted down like animals"; "assassinators of kings and emperors"
a member of a secret order of Muslims (founded in the 12th century) who terrorized and killed Christian Crusaders
operating with minimal human intervention; independent of external control; "automatic transmission"; "a budget deficit that caused automatic spending cuts"
like the unthinking functioning of a machine; "an automatic `thank you'"; "machinelike efficiency"
without volition or conscious control; "the automatic shrinking of the pupils of the eye in strong light"; "a reflex knee jerk"; "sneezing is reflexive"
a colorless nonflammable liquid used as a solvent for fats and oils; because of its toxicity its use as a cleaning fluid or fire extinguisher has declined