As a non-native English speaker, I have no idea what it means, and "a pejorative neologism for the conspicuous expression of moral values." just adds more words I don't know.

The term is characterized by the signaler's desire to show support for a cause without actually acting to support the cause in question. An important characteristic of virtue signaling is that there is little to no cost associated with the act; simple public vocalization in support of a cause has no cost to the signaler. In Bartholomew's original article, he describes virtue signaling as a public act with very little associated cost that is intended to inform others of one's socially acceptable alignment on an issue.

In a similar vein, political theorist and economist Sam Bowman argued that the term is hypocritical in that calling out another individual's actions as virtue signaling is simply another form of virtue signaling, executed to heighten the perceived status of the accuser.