| cognate |
| Definition: Words that share the same ancestor are cognate. |
| Example: Some Indo-European cognates of the English word night are: Nacht (German), natt (Swedish), noc (Czech), nyx (Greek), nox (Latin), and nakt (Sanskrit). Note: All of them derive from the Proto-Indo-European *nokt, night. |
| Etymology: The word derives from the Latin com, together + gnatus, born. |
| Oxford English Dictionary: Its first OED citation in this sense is from 1827: "A cognate language." (G. Higgins Celtic Druids 61) |