In linguistics, a semantic field is a group of words with related meanings. The words in a semantic field are usually part of a category, such as agricultural words or weather words. Semantic fields have applications in anthropology and computational linguistics. From an anthropological perspective, the types of words found in a semantic field within a given language often have cultural significance. The field of computational linguistics sometimes uses understandings of semantic fields to automatically generate definitions of words within a text.
Linguists generally agree that any given language has a finite number of semantic fields and sub-fields, although they may disagree about the exact categories. There are an infinite number of ways in which the words from various semantic fields can be combined, but only a limited number of categories of objects that can be verbalized. Within a semantic field, there may be a wide variety of words with overlapping meanings and various levels of formality. For example, "tree" and "conifer" are both words that fall into the broad category of "nature words." "Conifer," however, is both more specific and more formal or scientific.
On the level of application, the words within a given semantic field are often related to cultural attitudes about the objects that field describes. For instance, different languages have different numbers and types of words for family relationships. In Swahili, baba means both "father" and "uncle." This is indicative of the way family units often work in East African societies: uncles frequently play as great a role in one's life as one's father.
Another use of semantic fields is in computational linguistics, in which computer programs are written to produce or analyze text. Computational linguistics programs sometimes use semantic fields to extract information from a text. These programs may search for hypernyms, or words that describe a category, to find definitions of words within a text. For instance, "food" is a hypernym whose category members include "cookie" and "pork" and "sushi." A computational linguist might write a program to seek out definitions of various food items by seeking phrases like "is a food" or "is a type of food."