形容詞 faithless:

1. having the character of, or characteristic of, a traitor
   同義詞：traitorous, unfaithful, treasonable, treasonous

1. He was found to be a faithless worker.
   人們發(fā)現他是一個不忠實的工人。

faith.less

adj.（形容詞）
Not true to duty or obligation; disloyal.
背信的：不履行責任或義務的；不忠實的
Having no religious faith.
無宗教信仰的
Unworthy of faith or trust; unreliable.
靠不住的：不值得信賴或信任的；不可靠的

【引伸】
faith.lessly
adv.（副詞）
faith.lessness
n.（名詞）
<參考詞匯><同義詞>faithless,unfaithful,false,disloyal,traitorous,treacherous,perfidious,recreantThese adjectives mean not true to duty or obligation.
這些形容詞都表示對責任或義務不忠誠。
Faithless andunfaithful are approximately interchangeable and imply failure to adhere to promises, obligations, or allegiances:
Faithless 和unfaithful 基本可以互換，都含有對誓言、義務或聯盟的失信：
例句：
has never been faithless to her ideals;
從未失去她的信念；

例句：
an unfaithful spouse.
不忠的配偶。

False emphasizes a tendency to be faithless or deceitful:
False 強調具有虛情假意的傾向：
例句：
a false friend.
背信棄義的朋友。

例句：
.To thine own self be true,/And it must follow, as the night the day,/Thou canst not then be false to any man. (Shakespeare).One who isdisloyal is false to persons or things that are due allegiance:
.對你自己忠實，/并長久堅持，/你將不會對別人虛情假意. （莎士比亞）。Disloyal 的人對人或事業(yè)缺乏忠心和忠誠：

例句：
Disloyal staff members exposed the senator`s indiscretions to the press.
不忠實的工作人員把參議員們不慎重的行為暴露給新聞刊物。

Traitorous most commonly refers to disloyalty to a government or nation:
Traitorous 通常指對國家或民族的不忠：
例句：
a lying, traitorous insurrectionist.
一個撒謊的反叛分子。

Treacherous suggests a propensity for betraying trust or faith:
Treacherous 表示任何傾向于背信棄義的事：
例句：
.She gave the treacherous impulse time to subside. (Henry James).
.她一時沖動想退卻. （亨利·詹姆斯）。

Perfidious applies to what is abominably treacherous; it suggests vileness of behavior and often deceitfulness:
Perfidious 含有生來卑鄙，不能對人忠誠的意思：
例句：
the victim of a perfidious murder.
一次卑鄙謀殺的受害者。

Recreant implies a reprehensible, often cowardly disloyalty:
Recreant 含有應受責難的，通常膽小而不忠實的：
例句：
.while [Holland`s] sister provinces had proved recreant to [William of Orange] . (John Lothrop Motley).
.然而[荷蘭] 姐妹省區(qū)已證明了對 [威廉三世] 的背叛. （約翰·洛思羅普·莫特利）