Doublet (linguistics)

In etymology, two or more words in the same language are called doublets or etymological twins (or possibly triplets, etc.) when they have different phonological forms but the same etymological root. Often, but not always, the variants entered the language through different routes. Because the relationship between words that have the same root and the same meaning is fairly obvious, the term is mostly used to characterize pairs of words that have diverged at least somewhat in meaning. For example, English pyre and fire are doublets with only remotely connected meanings despite both coming ultimately from the same Proto-Indo-European (PIE) root.