Kiirust

Kiirust is the partitive singular form of the Estonian noun kiirus, which means speed or velocity of motion. In everyday Estonian, kiirust appears in sentences where the verb governs a partitive object, for example in phrases like suurendada kiirust (to increase speed) or hoida kiirust (to maintain speed). As a grammatical form, kiirust is commonly found in contexts describing changes to speed or measurements of speed.

In ordinary usage, kiirus refers to how fast something moves. Kiirust as a word form is most often seen when talking about the speed itself in a non-definite sense, or when the object of a verb is a quantity of speed. For instance, auto kiirust oli palju ehk the car’s speed was high, and auto kiirust suurendati means the speed of the car was increased. The phrase suur kiirusega (at high speed) uses kiirus in different grammatical forms to describe manner or degree.

In scientific and technical contexts, kiirus is the standard Estonian term for speed, defined as the magnitude of an object’s velocity. The unit of measure commonly used in Estonia follows international practice, with meters per second (m/s) and kilometers per hour (km/h) among the typical units. Kiirust as a form is encountered mainly in linguistic or applied contexts where partitive grammar is required.

Related terms include kiirendus (acceleration) and kiirus (speed in general).