n 1  :  a space (as an enlargement of a vessel or the cavity of a glandular acinus) in which a body fluid is stored  2  :  an organism in which a parasite that is pathogenic for some other species lives and multiplies without damaging its host : also  :  a noneconomic organism within which a pathogen of economic or medical importance flourishes without regard to its pathogenicity for the reservoir <rats are s of plague>  - compare CARRIERla   .
 
   
 
Similar sounding terms:  reserve air 
 
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