1. plural of isogloss; lines on a map that mark the boundaries between regions that differ in a particular linguistic feature (such as pronunciation, vocabulary, or grammar).
Usage: linguistics; technical term

Examples

• Linguists use isoglosses to show where speakers pronounce the word 'aunt' differently.
• The isoglosses on the dialect map revealed clear regional variations in vocabulary across the country.
• Isoglosses help researchers understand how languages and dialects are distributed geographically.
• The bundle of isoglosses in that region indicates a major dialect boundary.
• By plotting isoglosses, linguists can trace the historical migration patterns of language speakers.