14
border(noun, top, line, limit, edge)
12
doubtful(adjective, clear, open, delicate, certain)
11
boundary(noun, mark, top, limit, stroke)
11
edge(noun, mark, top, limit, stroke)
11
marginal(adjective, inexact)
10
unclear(adjective, clear, open, certain, uncertain)
9
equivocal(adjective, clear, open, delicate, certain)
9
frontier
9
line(noun, mark, stroke, border)
8
ambiguous(adjective, clear, open, delicate, certain)
8
margin(noun, edge)
8
mete
8
problematic(adjective, clear, delicate, certain, uncertain)
8
uncertain(adjective, clear, open, delicate, certain)
8
unsure(adjective, clear, open, delicate, certain)
8
verge(noun, limit, edge, border, extremity)
7
boundary line(noun, expression, idiom)
7
dubitable(adjective, clear, certain, uncertain, doubtful)
7
end(noun, top, limit, extreme, edge)
7
indecisive(adjective, clear, open, delicate, certain)
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APASmart Define. (2015). borderline thesaurus. Retrieved September 20, 2026, from https://smartdefine.org/borderline/thesaurus/synonyms
ChicagoSmart Define. 2015. "borderline thesaurus" https://smartdefine.org/borderline/thesaurus/synonyms (accessed September 20, 2026).
HarvardSmart Define 2015, borderline thesaurus, Smart Define, viewed 20 September, 2026, <https://smartdefine.org/borderline/thesaurus/synonyms>.
MLASmart Define. "borderline thesaurus" 13 April 2015. Web. 20 September 2026. <https://smartdefine.org/borderline/thesaurus/synonyms>