Etymology tree
Proto-Indo-European *h₃er-
Proto-Indo-European *h₃reyH-der.
Proto-Germanic *rinnaną
Proto-West Germanic *rinnan
Frankish *randijubor.
Old French randirder.
Old French randonbor.
Middle English randoun
English randon
English random
Proto-Indo-European *-kos
Proto-Italic *-kos
Latin -cus
Latin -icuslbor.
Portuguese -ico
Portuguese randômico
From English random + Portuguese -ico.