Long Vowel Rule (1): When a word has two vowel, usually the first vowel says its name and the second vowel is silent.
gill noun (FISH) âº [ 1  C usually plural ] the organ through which fish and other water creatures breathe. âº 2  us â [ C ] a measure of liquid that is equal to 0.142 litres or a quarter of a pint. âº 3  the organ through which fish and other water creatures breathe.
Medical Definition of Reservoir. Reservoir: 1. A place where something such as water is kept in reserve. 2. The part of a device in which something is kept in reserve or stored, as an Ommaya reservoir. 3. For an infectious agent, an animal, person, plant, soil, or other substance in which the agent normally abides. See: Reservoir of infection.