What does trojan mean?
Trojan is most widely known today as a type of malicious software. Such programs imitate legitimate files or applications so that users install or open them, after which they can steal data, damage systems, or enable further unauthorized access. The name comes from the Trojan horse of Greek legend, in which hidden soldiers entered a city concealed in a seemingly harmless gift. The word also refers to an inhabitant of ancient Troy and, as an adjective, to things connected with Troy, its people, or the Trojan War. In computing, Trojan is often used informally as if interchangeable with virus, but technically a Trojan is a kind of malware that disguises itself rather than necessarily replicating or infecting other files. The term is therefore useful in both literary and technical contexts, while its historical associations add a vivid sense of deception hidden behind an apparently harmless exterior.
A malicious computer program that hides its harmful purpose or unauthorized activity behind a legitimate appearance. Historically, the noun also means an inhabitant of ancient Troy.
"The attachment was a Trojan designed to install remote-access software."
In computing, the term is conventionally capitalized as “Trojan.”
Relating to ancient Troy, its inhabitants, or the legendary events and conflict associated with the city.
"The museum displayed several Trojan artifacts recovered from the archaeological site."
The adjective is normally capitalized because it refers to a historical and mythological proper name.
The standard plural is used especially for the inhabitants of ancient Troy. Individual malicious programs are more often referred to individually or collectively as Trojans without strict grammatical agreement.
"The Trojans resisted the Greek forces for many years."
Trojans get inside by pretending to be harmless—cybersecurity by way of Greek legend.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does trojan come from?
The word comes through Latin Troiānus, an adjective meaning “of Troy,” from Troia, the Latin name for Troy. Greek Troia was the ancient city's Greek name; related forms include Troilus, while Ilium, another name for Troy, lies behind the title Iliad. The computing sense uses the metaphor of the Trojan horse, reflecting software that enters a system under a harmless disguise.
Related word forms
How trojan is actually used
The conventional dictionary and technical form is capitalized as “Trojan”; lowercase “trojan” also occurs in general usage. The historical sense usually appears in literary, historical, or mythological contexts.
Easily confused with trojan
A virus replicates and infects other files or systems, whereas a Trojan typically disguises itself and does not need to replicate to cause harm.