köken: Etymology tree Proto-Indo-European *dʰrewgʰ-der. Proto-Balto-Slavic *draugás Proto-Slavic *drȗgъ Old Polish drugi Polish drugi Proto-Slavic *-o- Old Polish -o- Polish -o- Proto-Balto-Slavic *rindas Proto-Slavic *rędъ Old Polish rząd Polish rząd Proto-Indo-European *-nós Proto-Balto-Slavic *-inas Proto-Slavic *-ьnъ Old Polish -ny Polish -ny Polish drugorzędny From drugi + -o- + rząd + -ny.
köken: Inherited from Sanskrit *द्विसर (*dvisara, “two-stringed”), from द्वि (dvi, “two”) + सर (sara, “string, cord”) but with the first element following Sauraseni Prakrit 𑀤𑀼𑀯𑁂 (duve, “two”).
köken: From thứ (“-th”) + hai (“two”). "Second" could also be, less frequently, thứ nhì. As a name of weekday, calque of Portuguese segunda-feira (“Monday”, literally “second week day”).