From Old Norse dreyra, from dreyri (“blood”).
dreyra (weak verb, third-person singular past indicative dreyrði, supine dreyrt)
- (dated, intransitive) to bleed, to ooze blood from a slight wound
- Hann risti í lófa sér krossmark, svo að dreyrði.
- He cut a mark of the cross into his arm so that blood flowed.