notion [Lat. notio ‘concept, idea’] (also concept)

Idea which is conceived through abstraction and through which objects or states of affairs are classified on the basis of particular characteristics and/or relations. Notions are represented by terms. They can be defined like sets: (a) extensionally, by an inventory of the objects that fall under a particular concept; and (b) intensionally, by indication of their specific components. The current equating of ‘notion’ with ‘meaning’ or with Frege’s ‘sense’ (‘Sinn’) rests upon an intensional definition of ‘notion.’ ( also definition, intension)

Important syntactic category which makes up the majority of items in the English vocabulary. Nouns are marked morphologically in many Indo-European languages by the categories gender, number, and case. As the nucleus of noun phrases, they can be modified by attributes. Semantically, they are either concrete or abstract: concretes include proper nouns (Mary, Boston, Mozart), common nouns (person, cat, singer), collectives (mountain range, cattle), and other mass nouns (wine, gold, blood). Abstracts indicate properties (loyalty), events (dreams), relationships (animosity). measurements (hour, mile). For relevant information on word formation in nouns, composition, nominalization, word formation; for stylistic aspects nominal style. ( also declension, noun phrase)

Reference

Schachter, P. 1985. Parts of speech systems. In K. Shopen (ed.), Language typology and syntactic description. Cambridge. Vol. 1, 3-61.