faithful 
英 [ˈfeɪθfʊl]  美 [ˈfeɪθfəl] 
n. 信徒

adj. 忠实的，忠诚的；如实的；正确的

例句：
Older Americans are among this country's most faithful voters. 

较年长的美国人是这个国家最忠实的选民群体之一。

He was a discreet and faithful friend. 

他是个为人谨慎而忠诚的朋友。

He was awarded a medal as a mark of merit for long and faithful service. 

他被授予奖章，以表彰他长期忠诚奉献的功勋。

She had been faithful to her promise to guard this secret. 

她信守诺言，一直保守着这个秘密。