en
on the border
/ɑn ðə ˈbɔɹdɚ/
Definition
1
At or along the boundary line separating two countries, states, or regions.
2
Figuratively, in a position between two extremes, categories, or states; ambiguous or marginal.
Examples
Her cooking is on the border between gourmet and 'what did I just eat?'
He's living on the border of productivity and procrastination, mostly the latter.
The movie's plot is on the border of genius and total nonsense—critics can't decide.
That shade of gray paint is on the border between elegant and elevator music dull.