síde
This might be just a supplemental entry adding to an entry in the Main Volume.
Related §§ in Wright's OE Grammar:
In the OE text, the length is:indicated by acute accentsindicated by macronsnot indicated.
síde
AddWíde and síde geondsprang (cujus Gloria) longe lateque percrebruit, An. Ox. 2839. Oþ þá ancleów síde (mafortes) talo tenus prolixius (dependunt), 5336.
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A Combined List of Abbreviations.

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A Combined List of Abbreviations.