Specifically, north of the arctic or south of the antarctic circles. Literally, someone (-an) who casts shadows (Greek skia) all around (Greek peri-) -- as happens in polar regions in the summer, as the sun travels all around without dipping below the horizon. This is part of a series of unfortunately all-too-obscure words about people as defined by their shadows, including ascians from the tropics ("no shadow") and amphiscians on the equator ("shadow on either side").
We should never have let Martin vacation in Greenland -- he's just written another one of his odes on periscian hospitality.
---L.
