Isogloss
/ˈaɪ.səˌɡlɒs/noun
A boundary line on a linguistic map marking the distribution of a particular language feature.
Did you know?The word combines Greek isos, “equal,” with glōssa, “tongue,” linking modern dialect mapping to the ancient idea that language is literally an organ of speech.
Etymological Timeline
Ancient Greek
Greek
ἴσος (isos)
“Equal, even, or alike”
Ancient Greek
Greek
γλῶσσα (glōssa)
“Tongue; by extension, language or an unusual word”
19th Century
German
Isoglosse
“A term modeled on scientific map words such as isotherm, meaning a line marking an equal linguistic feature”
1899
German
Isoglosse
“A linguistic boundary marking where a dialect feature changes”
20th Century
English
isogloss
“A line on a map showing the geographic limit of a linguistic feature”