disloyal

1. ADJ Someone who is disloyal to their friends, family, or country does not support them or does things that could harm them. 不忠誠(chéng)的

She was so disloyal to her deputy she made his position untenable. 她對(duì)她的副手如此不忠誠(chéng)，以至於弄得他的職位岌岌可危。