AMON AMARTH: from Tolkien's Lord of the Rings, meaning "mount(ain) of doom."
ÁSATRÚ: Heathen faith, sometimes called the religion of the Vikings; defined as "belief in the gods."
CRUACHAN: a place in the West of Ireland that was the royal center of Connaught. There are many ring-forts in the area, as well as a cave called the Cave of Cruachan. Legend has it that this was the Celtic entrance to the 'Otherworld'. When the x-ians converted the Pagan Celts they renamed it as the gateway to hell. Also: a type of cattle from Cruachan in Scotland.
EINHERJER: In short: the chosen warriors of Oðin; defined as "single combatants."
FALKENBACH: hawk/falcon - stream/brook; also, a place in Germany. [Note: I don't know if either of these were the inspiration for the band name, but they're all I could come up with. Please contact me if you know otherwise.]
HELHEIM: world/realm of the goddess Hel, plus the lifeless, joyless, lightless dwelling of the dead; also called Hel and Niflhel (not to be confused with Niflheim).
HIMINBJORG: abode of the god Heimdall; likened to a 'watch tower' near Bifrost.
HIN ONDE: "the evil" (referring to the devil).
HROSSHARSGRANI: a reference to Oðin, meaning "horse-hair mustache"; I've also seen some rambling about it being the name of a Norse magician.
JOTUNHEIM: frosty and rocky world/realm of giants.
LANDVAETTIR: "spirits/wights of the land."
LINDISFARNE: early in the year 793 CE Northumbrian dwellers reported seeing exceptional flashes of lightning and fiery dragons in the air, later followed by vast famine. Soon thereafter [still in 793] the Vikings raided, plundered, and pillaged the monastery at Lindisfarne, thus coronating 793 as a sacred Heathen year!
MÅNEGARM: "moon - dog/wolf"; also, a wolf that lives on the blood of dying humans, and at Ragnarök he hunts down--and swallows--the moon
MENHIR: "long stone."
MITHOTYN: Mit-Odin, "the false Odin," or "the one beside Odin."
ODHINN: one of countless variations of the Norse god's name; also spelled Odin, Wotan, Wodan, Woden, Oðin, and so forth, plus he is known by a seemingly endless list of aliases (especially in the form of kennings).
OTYG: Swedish for rubbage, mischief, and nuisance; also, a collective name for the dark creatures in Scandinavian folklore.
RAGNAROK (UK): "the doom of the gods."
SOLHVERV: "solstice."
THYRFING: a sword made by dwarves.
TUMULUS: Earth-covered megalithic grave (barrow) without a corridor.
VALHALLA: 'hall of the slain'; the hall where Odin feasts with the slain, and the Valkyries.
VANAHEIM: the watery world/realm of the Vanir, associated with harvest, fertility, death, etc..
VINTERSORG: "winter sorrow"; also, taken from a book series called Isofolket (translated: The Ice People).
WINDIR: ancient Norse for "warrior."
(tja, ik ben nog niet helemaal bij de les) 
:
