Complementary things are different from each other but make a good combination.
例句
To improve the quality of life through work, two complementary strategies are necessary...想通過工作提高生活質量，需要兩個相輔相成的策略。Many plain tiles and complementary borders are also available...多種素色的瓷磚和配套的腰線也在售
ADJ
補充醫學的(不同于西醫的治療方法，如針灸、順勢療法)
Complementary medicine refers to ways of treating patients which are different from the ones used by most Western doctors, for example acupuncture and homoeopathy.
例句
...combining orthodox treatment with a wide range of complementary therapies.把傳統的治療方法與各種補充療法結合
英英詞典釋義
Noun
1. a relation between two opposite states or principles that together exhaust the possibilities
2. the interrelation of reciprocity whereby one thing supplements or depends on the other;