/bɒb ||; bɑb/verb (bobbing;bobbed) [I,T] to move quickly up and down; to make sth do this （使）上下快速移动: The boats in the harbour were bobbing up and down in the water. 港口内的小船在水中飘荡。She bobbed her head down below the top of the wall. 她的头在墙顶下面一上一下地移动。 bob up to appear suddenly from behind or under sth （从某物后面或下面）突然出现: He disappeared and then bobbed up again on the other side of the pool. 他不见了，然后又突然出现在水池的另一头。