What is the meaning of Trojan?

Malware that appears to perform or actually performs a desired task for a user while performing a harmful task without the user's knowledge or consent.

Describing a satellite (moon or minor planet) that shares an orbit with another

To infect (a system) with a trojan.

trojan, Trojan horse (computing)

alternative form of trojanar

Trojan, Trojan horse (malicious program that is disguised as legitimate software)

Trojan horse (malicious program disguised as legitimate software)

Source: wiktionary.org