un-wæstmbǽre
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.
un-wæstmbǽre
AddWíse láreówas sǽdon seó eorþe wǽte micele unwsestmbǽrre æfter þám flóde þonne heó ǽr wǽre tradunt doctores terrae vigorem et fecunditatem longe inferiorem esse post diluvium quam ante, Angl. vii. 36, 348.
This is a supplementary entry with editorial changes to an entry in the main volume of the dictionary. Look under the 'Possibly connected entries' below, or for the same headword in the list to the left.

A Combined List of Abbreviations.

Abbreviation not recognized. See:

A Combined List of Abbreviations.