köken: From Old Norse aga (“to threaten”), from Proto-Germanic *agaz (“fear, dread”), from Proto-Indo-European *h₂egʰ- (“to be depressed, afraid”). Cognates include Ancient Greek ἄχος (ákhos, “distress, pain”), English ey and awe.
köken: Attested since the 15th century. From Old Galician-Portuguese (compare Old Galicia-Portuguese rancura, 13th century, Cantigas de Santa Maria), from Latin rancor.
estauan en moytas cartas de scomoion et testemoyos et eran en grande descordia et anduan en odios et rancores
1612, Pedro Vázquez de Neira, "Soneto", in Gómez Tónel, Exequias
köken: Possibly from Proto-Albanian *melana (“black”), from Proto-Indo-European *melh₂-n-os, from *melh₂- (“black”) (compare Latvian męl̃ns (“black”), Serbo-Croatian malina (“raspberry”), Ancient Greek μέλαινα (mélaina, “black”)). For sense development from ‘black’ to ‘grudge, resentment’, compare zi. Alternatively, figurative use of 'Etymology 2' ("swelling").