资料来源 : pyDict

无过失地;正确地

资料来源 : Webster's Revised Unabridged Dictionary (1913)

Unerringly \Un*err"ing*ly\, adv.
   In an unerring manner.

资料来源 : WordNet®

unerringly
     adv : without making errors; "he unerringly fixed things for us"