köken: From Old Norse fjǫrð, from Proto-Germanic *ferudi (“last year”), from Proto-Indo-European *peruti (“last year”, literally “on the other side of a year”). The development from rð > l (originally /ɽ/) is characteristic of the traditional dialects of central and northern Sweden, compare e.g. vålnad, hin håle.
köken: Inherited from Old Czech loni, lóni, from Proto-Slavic *olni, from Proto-Indo-European *ol-nei. Cognate with Polish łoni, Slovak vlani, Slovene láni, Serbo-Croatian lȃni/ла̑ни, Russian лони́ (loní), and Latin ōlim (“once”).
köken: Inherited from Proto-Slavic *olni, from Proto-Indo-European *ol-nei. Cognate with Slovene láni, Czech loni, vloni, Serbo-Croatian lȃni/ла̑ни, Russian лони́ (loní), and Latin ōlim (“once”).
köken: An old compound, with as first part Proto-Indo-European *per- (“over”), and the second part a different term in different Indo-European languages (in Ancient Greek and Sanskrit, the second term was probably *ut- < *wet- (“year”), i.e., *per-ut(i)-). In the Baltic case, it is possible that the second element was Proto-Indo-European *sénos: *per-sénos > per-enos > Proto-Baltic *pernas > Latvian…
köken: From Middle Welsh yrllyned. Seemingly formed as a derivative of blwyddyn / blynedd (“year”) with some prefix, though the details are unclear. Compare eleni (“this year”), and Breton warlene (“last year”).
köken: Literally, “in (the) former”. The second element is likely a corruption of Old Norse fjǫrð (“last year”), which gives the second element in Swedish i fjor (“last year”), Danish i fjor (“last year”), Norwegian i fjor (“last year”).