Subtweet is short for subliminal tweet. In other words, it's an X (formerly Twitter) message about someone that doesn't actually mention their @username or real name.

Subtweeting is often used to make a comment about someone, but to keep the identity of that person vague. This way, no one (probably) can figure out who you are talking about.

You may have seen these types of posts on Facebook and other social networks. Examples include cryptic status updates or captions where the poster clearly addresses their message to someone without mentioning the person's name.

Subtweets are often used to say something negative about someone. However, subtweets can also show admiration for someone if you are too shy to show it.