duality
/djuːˈælətɪ/noun
(pl. -ies)
1
- mass noun the quality or condition of being dual两重性：
this duality of purpose was discernible in the appointments.
这一目的的两重性可从任命中看出。
1.1
- Mathematics the property of two theorems, expressions, etc. being dual to each other.【数】对偶性。
1.2
- Physics the quantum-mechanical property of being regardable as both a wave and a particle【物理】二象性; 对偶性。
2
- an instance of opposition or contrast between two concepts or two aspects of something; a dualism对立; 对比：
the simple dualities of his youthful Marxism: capitalism against socialism, bourgeois against prole.
他那不成熟的马克思主义的简单对立：资本主义与社会主义相对立, 资产阶级与无产阶级相对立。
词源
late Middle English: from late Latin dualitas, from dualis （see DUAL）.