borderline
🇺🇸
/ˈbɔːrdərlaɪn/
🇬🇧
/ˈbɔːdəlaɪn/
Something that is borderline is not clearly one thing or another, or not clearly good or bad.
The weather today is borderline between being sunny and rainy.
The borderline is the line that separates two different things or places.
The borderline between the two countries is marked by a river.