A noun, such as furniture, water, or honesty, that cannot be modified by the indefinite article, does not occur in the plural, and is often preceded by modifiers such as some or much or by a phrase containing a unit of measurement. Some nouns can function both as mass nouns (There are sixty boxes of tile in the warehouse) and as count nouns (We had to cut a tile in half to fit the end of the row). Also called noncount noun. See Usage Note at collective noun.