n.

a lightweight handheld collapsible canopy

a formation of military planes maintained over ground operations or targets

"an air umbrella over England"

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"

Umbrellas
Umbrellas
Umbrellas and flagships: efficient conservation surrogates or expensive mistakes?
Molecular Umbrellas
Design and Synthesis of Molecular Umbrellas
Molecular umbrellas: a novel class of candidate topical microbicides to prevent human immunodeficiency virus and herpes simplex viru...
Chemical Evidence for Transbilayer Movement of Molecular Umbrellas
Stabilizer retention device for beach umbrellas
EMPIRICAL VALIDATION OF A METHOD FOR UMBRELLA SPECIES SELECTION
CARNIVORES AS FOCAL SPECIES FOR CONSERVATION PLANNING IN THE ROCKY MOUNTAIN REGION