To unfollow someone is to stop having their posts appear in your feed on a social network. You had chosen to follow them; now you undo that choice, and their messages stop reaching you.

The dictionary line here mentions Twitter, because that is where the word was born and where dictionaries first caught it. But it long ago spread everywhere — Instagram, Facebook, YouTube, TikTok, Threads. In Chinese-speaking places the same action is 取消追蹤 or 退追.

Two things students should know about how it really feels. First, unfollowing is much softer than blocking or deleting. If you unfollow someone, they can still see your posts, still message you, and usually will not be told — so people use it to quietly clear their feed of a noisy classmate or a colleague who posts too much, without any argument. It is the polite exit. Second, precisely because it is quiet, it can still hurt: people do notice when their follower number drops, and 'she unfollowed me' is a real small social wound among younger users.

Grammatically it behaves like any regular verb — unfollow, unfollows, unfollowed, unfollowing — and you can also say 'I got a lot of unfollows this week', using it as a noun.

It is a young word and completely informal. Do not put it in a formal essay unless you are actually writing about social media.