Monocausal is an adjective that describes something that has only one cause or origin. Other synonyms for this word include singular, unicausal, or unifactorial. All of these words describe a situation where a single factor or cause is believed to be responsible for a specific outcome. Other related words include elemental, fundamental, and underlying. These words suggest that there is a basic or essential cause or factor that is responsible for a specific result. In contrast, the opposite of monocausal might be described as multifactorial or multicausal, suggesting that there are many different factors or causes that contribute to a particular outcome.