A group of words that are related because they are from the same area of knowledge or interest, e.g. the semantic field of agriculture includes: farm, farming, tractor, meadow, crop, etc. This is sometimes also called lexical field. Semantic fields can be important in the use of metaphor. A metaphor is a description of a thing from one semantic field (e.g. football) spoken of as if it were from a very different semantic field ('the home side gunned down the opposing side with ease' - the semantic field of war).