merigen
This might be just a supplemental entry adding to an entry in the Main Volume.
In the OE text, the length is:indicated by acute accentsindicated by macronsnot indicated.
merigen
I. add: — Wæs þá geteald ǽfen and merigen tó ánum dæge, Lch. iii. 232, 12. Drince on morgenne scenc fulne þises drences, tó middes mergenes stande eástweard, ii. 116, 7. Ofer ealle niht oð leóhtne mergen, R. Ben. 47, 9. II. add Swá swá godspel sægð : 'Ne þenc þú be mergene,' Hml, S. 31, 57. Heó swór Helias sceolde ðæs on mergen (merigen, v. l. ) sweltan, 18, 158. v. Sunnan-merigen.
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A Combined List of Abbreviations.

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A Combined List of Abbreviations.