A camera that has a mirror directly in the path of light traveling through the lens that reflects the scene to a viewing screen.
camera that allows the photographer to view and focus the exact scene being photographed
In general, any camera that uses a mirror (or prism, or both) to allow the photographer to actually view through a lens. This basically means a 35mm SLR, but also includes medium format SLRs and TLRs.
a camera with a built-in mirror that reflects the scene being photographed onto a ground-glass viewing screen. See Single-lens reflex, Twin-lens reflex.
A camera that uses a mirror to reflect light onto a ground glass for viewing and focusing.
camera system which uses a mirror to reflect incoming image rays on to a ground glass screen, providing a system of viewing and focusing. See also SLR.