[ .bæk'dɒ: ]
BNC词频 37219 COCA词频 24498
a. 秘密的
n an undocumented way to get access to a computer system or the data it contains
n an entrance at the rear of a building
n a secret or underhand means of access (to a place or a position)
英汉双解字典由 ECDICT 提供