Definition of "bordering" []

• Present participle of border. (verb)
• Having a common boundary or border (adjective)

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• "He waggled his eyebrows at me, his expression bordering on a leer."
• "The bulging eyes and fierce, gummy smile: it was an expression bordering on hysteria, and the intervening years had done nothing to dampen it."
• "Captain Spock observed their surroundings with an expression bordering on exasperation, then turned to survey the landing party."