ˈ ̷ ̷ ̷ ̷ˌgläs, -lȯs noun
( -es )
Etymology: International Scientific Vocabulary is- + -gloss (from Greek glōssa language, tongue) — more at gloss
1. : a boundary line between places or regions that differ in a particular linguistic feature
the isogloss separating Low German maken “to make” from High German machen
dialect boundaries can be established only by means of isoglosses — Hans Kurath
2. : a line on a map representing an isogloss
• iso·gloss·al | ̷ ̷ ̷ ̷| ̷ ̷əl adjective