Short for 'thread' on internet forums or social media — a sequence of posts on a particular topic.
新しいスレ立てていい？
Can I start a new thread?
その話題のスレ、もう1000レス越えてるよ。
The thread about that topic already has over 1,000 replies.
このスレは情報まとめが便利だからよく参照している。
I often refer to this thread because its information summary is useful.
荒らしが入ってこのスレはもうめちゃくちゃだ。
Trolls got in and this thread is already a mess.