Czech druh

← Proto-Balto-Slavic *draugás (inherited)

← Proto-Indo-European *dʰrewgʰ- (derived)

← Proto-Slavic *drugъ (inherited)

→ Czech poddruh (prefix)

→ Czech dobrodruh (compound)

→ Czech soudruh (affix)

→ Czech družný (suffix)

→ Czech družstvo (suffix)

→ Czech druhový (suffix)

→ Polish druh (cognate)