The dead in Christ will rise first; then we who are alive, who are left, shall be caught up together with them in the clouds to meet the Lord in the air; and so we shall always be with the Lord. (1 Thess. 4:16–17)
This is where the Latin word “rapiemur” comes from. St Paul talks about being “caught/raised up”. The word Rapture is connected to this word. The Latin Vulgate translates the Greek ἁρπαγησόμεθα as rapiemur, from the verb rapio meaning “to catch up” or “take away”.
Therefore Catholics believe that those faithfuls who are still on earth at the Second Coming of Christ will be taken up and gathered together with those who died in Christ. They will meet Christ in the air as he comes in glory. We do not however hold that this event shall take place before the coming of Christ, also we do not really use the word “Rapture”. But the concept of the word is part of the Church’s doctrine on the Second Coming (Parousia, General Judgement)