There are a large number of fields of semantics ranging from actions to emotions. A semantic field is a group of words with a similar meaning that are always of the same grammatical class. This makes defining broad or narrow semantic fields difficult because many words can be spread across different fields. In its most simplistic sense, such fields represent types of objects, actions, qualities and descriptions.

Semantics is the study of the meaning of words. It seeks not just to ascertain that an apple is an apple, but also why it is called an apple. This study is divided into words, phrases, signs and symbols. Each of these types is called a signifier. Semantics often combines well with other modes of linguistic study such as lexicography, etymology, syntax and philology.

These fields of semantics are organized by word meaning. Semantic fields are similar to the lexical field theory as posited by Jost Trier in 1931. The theory holds that many words gain their meaning due to a relationship with another word; for example, why we get "sanctuary" and "sanctify" as well as "mortuary" and "mortify."

The major problem of combining semantic fields, as Trier points out, is that many words have overlapping meanings. This means that some words will need to be put into different fields depending on their meaning at the time. Words with many meanings such as “set” are called polysemous words and are placed in many fields. It is also common for words, such as “man,” to go through a semantic shift, changing both their meaning — in this case, from “human being” to a “male human” — and their semantic field.

Defining fields of semantics comes down to personal opinion. Many fields can be broken down into actions, descriptions, humans, and perception. Fields are then subdivided into more specific categories.

Perception is subdivided into its core elements. These include subjective perceptions such as spacial awareness and the senses. There are also objective perceptions including time.

Human-based fields include the purely biological — names for the body parts and its functions. They also include human emotions, which can be divided in many ways, such as into positive and negative. Other fields of human semantics include language, art, judgment and thought.

The physical world ranges from descriptions of the universe to the biological makeup of a single cell or atom. It includes the basic elements, topography and geology. It also includes words for animals, plants, fungi and other life forms.

Actions cover verbs in any lexicon. Verbs and actions are divided by group or function. These might be aggressive or passive as in the difference between seeing and watching. Such actions also include processes in the world and how a language describes how the world works.

Descriptions are adjectives that can be broken down into objective and subjective. Objective adjectives are ones that are innate and are not an opinion. Objective adjective fields of semantics includes colors, dimensions, materials and textures. Subjective ones depend on a personal opinion and include good and bad.