shrithe
To move; to proceed; to creep, roam, wander.
intransitive
He realized the monster meant to attack Heorot after the blue hour, when black night has settled over all— when shadowy shapes come shrithing dark beneath the clouds.
Where it comes from
Coined by English writer and translator Kevin Crossley-Holland (born 1941): a semi-learned borrowing from Old English sċrīþan (“to go; take one's way to a place; go about; wander”), from Proto-West Germanic *skrīþan, from Proto-Germanic *skrīþaną (“to walk, go, slither, crawl”). Cognate with Dutch schrijden (“to stride”), German schreiten (“to stride, step, proceed”), Icelandic skríða (“to slither, creep, crawl”). As shrithe was a class I strong verb in Old English, were it inherited, the expected forms would be: simple past: *shrothe, and past-participle: *shrithen. It is important to note, however, that Crossley-Holland did not use these forms and therefore has ahistorically treated shrithe as weak verb.
Adapted from the Wiktionary entry shrithe (CC BY-SA 4.0).