word class 
noun
A category of words of similar form or function; a part of speech.On the lexical level, paradigmatic contrasts indicate which words are likely to belong to the same word class (part of speech): cat, dog, parrot in the diagram are all nouns, sat, slept, perched are all verbs....
- Ultimately, however, a word class emerges as a function of its role within a constructional schema.
- The present study additionally demonstrates the importance of the first letter of a noun for identifying its word class at an early stage of sentence processing in German.