大致明白某人所说的话
to understand the general meaning of what someone is saying
  She could see from his expression that he caught her drift immediately.
 You can make a point quite subtly and you know that the audience will get your drift.
 I suspect she didn't catch your drift.
 It took me a moment but then I caught his drift.
 I didn't hear everything you said but I think I got your drift.
 See also: drift noun (MEANING)