1. The ambience created by a sound occurring in a room.
2. A digital or modeling effect designed to simulate the ambience created by a sound in a room. Typically room reverbs are short (less than a second), though obviously a large room could result in a longer reverb. Characteristics of a room reverb might include a short pre-delay, simulation of strong early reflections; simulation of the absorptive or reflective properties of wall, ceiling, and floor surfaces; simulation of the reverb tail dispersion through the room; and more.