Perfidious /pərˈfɪdiəs/ adj. 不忠的; 不可信的
Meaning: Deceitful and untrustworthy, especially in betraying vows or allegiance
前缀: per- 穿过, 透过(perfect)
词根: fid-相信(confident)
后缀: -ous 形容词后缀
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