What is the meaning of Shitpost?

A worthless or superficially meaningless post on a message board, newsgroup, or other online discussion platform, often intended to derail or distract from relevant conversation.

A seemingly worthless or superficially meaningless image, video or piece of text posted to a social media platform that is intended to be humorously or ironically enjoyed.

To make a shitpost.

Source: wiktionary.org