1.
boundary, dividing line, border
The line or point where one thing ends and another begins, whether physical or abstract.
Usage
Often used for abstract boundaries (between concepts, states, or categories) rather than just physical borders. The pattern AとBの境目 (the boundary between A and B) is standard.
Similar words
境界 is more formal and technical (often used for property or territorial borders). 境目 is more natural for abstract or everyday distinctions.
Common collocations
Related Words
Synonym:
境界 (boundary (formal))