chocker,ducker是什么意思

ducker ['dʌkə]
n. 潜水者；养鸭者；潜水鸟
Ducks clucked under the docks with a ducker in duck ducking into the dark.
鸭子在码头下面咯咯直叫chocker，一个穿帆布服的猎鸭人一闪隐入黑暗中。