border on is a verb meaning "come near or verge on, resemble, come nearer in quality, or character". It carries one recorded sense.
come near or verge on, resemble, come nearer in quality, or character
“This borders on discrimination!”
“His playing approaches that of Horowitz”
Definitions, synonyms and semantic relations for border on come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.