On much of its length, this border has not been defined.
The border is largely defined along the crest of the range.
But its borders were not defined and good relations with Ethiopia never developed.
The border between the terms is vague and poorly defined.
"The border is mostly defined by major rivers in full flood."
Its borders, at least as of designation in 1966, were defined by the city limits.
The border between these is sometimes defined using a circle of confusion criterion.
I think it's more that borders are being defined.
Here's a pretty homogenous group that has fairly defined borders if you ask them.
The borders had been defined by demarcation commissions in 1947.