Attested: Lopocarium occurs at the end of one of RC's sequences of names, just before a jump to a new sequence along Hadrian's Wall. Arguments by R&S and others for a composite **Corielopocarium are unjustified because the preceding name Corie (almost certainly Corbridge) is so clearly separate.
Where: Uncertain, but most likely where the Roman road from Corbridge to the Roman fort at Επιακον crossed the valley of the river Allen, after heading across moorland south of Hexham. When Selkirk (1995, 123–126) wrote about this road, it was thought to pass through Old Town, near Allendale, but recent work written up by Toller and Haken in the Autumn 2017 RRRA Newsletter has clarified much of the course of this road. It would have crossed the West Allen somewhere near Catton, at about NY822573.
Name Origin: To explain Lopo- three possibilities seem strong:
(1) Germanic words such as English lope and Dutch lopen essentially mean ‘to walk, to run’, appropriate to a road likely to have been walked by men and packhorses, so a stopover place half way along its 22-mile length might make sense.
(2) Latin lupus ‘wolf’ might have had a Celtic counterpart *louerno- ‘fox’ invoked by Delamarre (2003:207) to explain some Romano-British personal names such as Lovernianus. And -arius was much used as a suffix in Latin.
(3) Greek λοπος ‘peel’, of uncertain etymology, but possibly from PIE *lep- ‘skin, peel’ or from *lop- ‘flat’, whose English descendants arguably include leaf, leper, and lop-sided. Either way that might fit the way that the lead sulfide ore galena tends to occur in thin veins.
The -carium ending has many possible origins, including Greek καρυον ‘nut’. Also there are many parallels in English to consider: care from OE cearu ‘sorrow, grief’ might suit a traveller's rest place; carr ‘bog’, said to come from Norse, might suit a river crossing without a bridge; carr ‘rock’, from PIE *kar- ‘hard’ might fit outcropping rock; but possibly best is carry, which has no certain etymology, but fits the man-plus-packhorse idea. In short, maybe this was a lope-carry place.
Notes: Analyses of this name presented here have evolved greatly. At first the wolf idea seemed best, because wolves used to be common in Northumberland, to the point where they were still being actively persecuted in the 1300s. Plenty of modern place names there originally contained wolf, though whether that came from the animal or a personal name is unknown. They include Wolf Hole in the Rothbury Forest, well north on the Devil's Causeway Roman road, with suitable rocks, but maybe too far north. Ushaw Moor, Wolsingham, and Wolviston may be too far south. Wooley is in the right area. Then the argument in favour of Greek seemed stronger, because (a) the neigbouring name Επιακον is manifestly Greek, (b) Romans were avid for silver, mostly extracted from lead ores using technology pioneered by Greeks near Athens, and (c) the Allendale area had (many centuries later) some of the richest silver-producing lead mines in the world. What has pushed the Germanic loping idea into first place is a comment by recent investigators that this Roman road can never have been suitable for wagons.