Boundary adjectives are listed in this post. Each word below can often be found in front of the noun boundary in the same sentence. This reference page can help answer the question what are some adjectives commonly used for describing BOUNDARY.
absolute, actual, additional, administrative, alaskan, american, ancient, anterior, appropriate, arbitrary, artificial, blurred, bottom, british, called, canadian, certain, circular, clear, closed, colonial, common, correct, corresponding, cultural, curved, cut, defined, definite
different, dimensional, dirichlet, disputed, distant, distinct, east, eastern, effective, entire, ethnic, exact, exterior, external, extreme, farthest, final, firm, first, fixed, former, free, french, future, fuzzy, general, geographic, geographical, grain
great, horizontal, ideal, imaginary, impassable, important, indian, initial, inner, interior, internal, international, invisible, irregular, last, lateral, left, legal, local, long, lower, many, maritime, marked, mexican, mixed, moral, municipal, narrow
national, natural, new, north, northeastern, northern, northernmost, northwest, northwestern, official, old, only, opposite, organizational, original, other, outer, outermost, outside, own, parish, particular, periodic, permanent, permeable, physical, political, porous, possible
posterior, precise, prescribed, present, professional, proper, racial, real, rear, right, rigid, russian, sacred, same, second, sharp, simple, single, smooth, social, solid, south, southeastern, southern, southwestern, spanish, specific, state, strict
strong, such, suitable, symbolic, t, temporal, territorial, tertiary, texan, thermal, thin, traditional, true, turbulent, ultimate, unsettled, upper, usual, utmost, various, venezuelan, vertical, very, visible, west, westerly, western, whole
Hope this word list had the adjective used with boundary you were looking for. Additional describing words / adjectives that describe / adjectives of various nouns can be found in the other pages on this website.