柯林斯詞典auxin /???ks?n/ 1. N any of various plant hormones, such as indoleacetic acid, that promote growth and control fruit and flower development. Synthetic auxins are widely used in agriculture and horticulture 植物生長素 返回 auxin劍橋詞典a chemical substance that controls growth in plants 茁長素（植物生長素） 返回 auxin