listen in 1. 收听 (广播等) (to) listen in to the President's speech 收听总统的讲演 I just don't find such programmes worth listening in to. 我觉得这样的节目简直不值得收听。 2. 偷听，监听 (on, to) He listened in on my conversation with Mary. 他偷听我和玛丽的谈话。 Somebody is listening in to our telephone conversation. 有人在窃听我们的电话交谈。