The Greek word is episunagoge. It refers to a meeting, assembly, or gathering. This version of the word occurs only twice in the entire New Testament. I’ve made its English equivalent bold and underlined in the two verses that follow.
“not neglecting to meet together, as is the habit of some, but encouraging one another, and all the more as you see the Day drawing near.” (Hebrews 10:25, ESV)
“Now concerning the coming of our Lord Jesus Christ and our being gathered together to him, we ask you, brothers,” (2 Thessalonians 2:1, ESV)
This gathering refers to two different but linked meetings. The first is the ongoing regular meeting of believers. The second refers to the final gathering of believers together when Christ returns. That the two gatherings are linked is clear, for the first, which deals with the ongoing regular gathering of believers, specifically mentions “the Day”, an overt reference to Christ’s return.
If you’re looking forward to the one, then don’t neglect the other. If you’re looking forward to the gathering of believers with Christ upon his return, then don’t neglect the regular gathering of local believers where Christ is in their midst.
We live in a day when it is increasingly stylish to “follow Jesus” without any connection to a local assembly of believers. Some may even try to talk you out of the need for such a connection. Don’t fall for it.