etymon

An etymon is the original form of a word from which a later form derives, typically in the ancestor language or in the source language of a loanword. In historical linguistics and lexicography, the etymon represents the historical form that gives rise to the present-day word through processes such as sound change, semantic shift, or borrowing. The concept helps explain why related words in different languages resemble one another or why a modern word bears a certain core meaning.

The word etymon itself comes from Greek, meaning the true sense or true form of a word. The term is used to contrast with the attested modern form, the phonetic and semantic shape the word has acquired over time. Etymons can be reconstructed forms in proto-languages or the earliest recorded forms found in historical texts, or the corresponding form in a source language for a loanword.

In practice, etymons are used in etymology and dictionary notes to indicate the ancestor of a word. For example, the English word salary has as its etymon Latin salarium, which referred to a salary or payments associated with salt. Etymons also help identify cognates across related languages, explain irregular spellings, and trace the pathways of borrowings between languages. While the etymon provides a historical anchor, the modern word may diverge substantially in form and sometimes in sense.