unfailing
/ˌʌnˈfeɪlɪŋ/adjective
1- without error or fault永远正确的; 永不犯错的：
his unfailing memory for names.
他从不出错的人名记忆。
1.1
- reliable or constant可靠的; 持久的：
his mother had always been an unfailing source of reassurance.
他母亲一直是他自信的可靠根源。
派生词