n. a relation of direct opposition
n. the gears by which the motion of a machine can be reversed
n. an unfortunate happening that hinders or impedes; something that is thwarting or frustrating
n. the side of a coin or medal that does not bear the principal design
n. 相反, 背面, 倒退, 挫折, 失败
a. 反面的, 相反的, 反向的, 颠倒的
vt. 使颠倒, 使逆转, 使倒退, 使反向
vi. 倒退, 反向, 倒转, 反转
[计] 反转