Irregular Plurals Definition
There are many different types of irregular nouns in English that do not add a final '-s' to make the plural. Some do not change (SHEEP), while others change internal letters (WOMAN- WOMEN), or add letters (CHILD- CHILDREN, OX- OXEN).
See Also:
Concrete Noun; Abstract Noun; Proper Noun; Adjectival Noun; Noun as Adjective; Collective Noun; Mass Noun; Substantive