| reverberation time | |
| —n | |
| a measure of the acoustic properties of a room, equal to the time taken for a sound to fall in intensity by 60 decibels. It is usually measured in seconds | |
| a children's mummer's parade, as on the Fourth of July, with prizes for the best costumes. |
| an arrangement of five objects, as trees, in a square or rectangle, one at each corner and one in the middle. |