Trój

Trój is a linguistic root used in several Slavic languages to denote the number three. In Polish, the form trój- functions mainly as a combining form in compounds and is encountered in proper nouns. It does not normally stand alone as a modern lexical item outside fixed terms.

Origin and distribution: The prefix derives from Proto-Slavic *trojь and has cognates across Slavic languages, such as Czech troj- and Slovak troj-, reflecting a common numerical root that prefixes or inflects words referring to triads or triadic attributes. In some languages the form appears with various diacritical marks depending on phonological rules.

Usage in Polish: Examples include trójkąt (triangle), trójnóg (tripod), and trójwymiarowy (three-dimensional). In set phrases, the combining form appears in Trójca Święta (Holy Trinity) and Trójmiasto, the collective name for the three coastal cities of Gdańsk, Sopot, and Gdynia.

Other languages: Czech uses troj- in words such as trojúhelník (triangle) and trojice (the Trinity). Slovak also uses troj- in trojuholník (triangle) and trojica. These forms show the shared Slavic heritage of the root and its broad application to triadic concepts and objects.

See also: tri-, trojka, trifecta. The term trój and its cognates commonly function as prefixes indicating the quantity three in descriptive terms, measurements, mathematics, and religious or geographic names across Slavic languages.