Nomina actionis (NA) are nouns that have the meaning of an action, process, or state, and usually have a verbal origin. This category of words is a special hybrid type in all Slavic languages, because it combines properties of both verb and noun.

The center of the category are nouns derived from verbs and having a process meaning, e.g., Po czytać ʻto read’ → czytanie ʻreading’, Uk doslidžuvat…