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(xiàn)他是一個(gè)不忠實(shí)的工人。

faith.less

adj.（形容詞）
Not true to duty or obligation; disloyal.
背信的：不履行責(zé)任或義務(wù)的；不忠實(shí)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(duì)責(zé)任或義務(wù)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(duì)誓言、義務(wù)或聯(lián)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(qiáng)調(diào)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(duì)你自己忠實(shí)，/并長久堅(jiān)持，/你將不會(huì)對(duì)別人虛情假意. （莎士比亞）。Disloyal 的人對(duì)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(shí)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(duì)國家或民族的不忠：
例句：
a lying, traitorous insurrectionist.
一個(gè)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(shí)沖動(dòng)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(duì)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(yīng)受責(zé)難的，通常膽小而不忠實(shí)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(duì) [威廉三世] 的背叛. （約翰·洛思羅普·莫特利）