Definitions

1. noun

a branch of geology dealing with the measurement of the rate of movement of geological processes, especially the rate of erosion, and the use of this information in the interpretation of the history of the Earth’s surface

“The team of geologists employed various tachymetric techniques to study the effects of glacial erosion on the landscape.”

2. noun

the measurement of the rate of change of something, especially a physical quantity

“The scientists used tachymetry to measure the rate of chemical reactions and understand the underlying mechanisms.”