The semantic field of a given word shifts over time — see "semantic shift." For example, the English word "man" used to mean "human being" exclusively, while today it predominantly means "adult male," but its semantic field still extends in some uses to the generic "human" (see Mannaz).
Overlapping semantic fields are problematic, especially in translation. Words that have multiple meanings (called polysemous words) are often untranslatable, especially with all their connotations. Such words are frequently loaned instead of translated. Examples include "chivalry" (literally "horsemanship," related to "cavalry"), "dharma" (literally, "support"), and "taboo."
Further semantic shifts of loaned terms may lead to further complications. For example, the Arabic "islām" has a generic meaning of "peaceful submission, piety". The term as loaned into English, "Islam," has a meaning strictly confined to the religion (deen) initiated by Muhammad, replacing the now deprecated term Mohammedanism. This state of affairs may lead to misunderstandings in discussions on the origin or nature of "Islam".