sacu
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.
sacu
I. AddSwá micele hefigre sace geþanca flǽsclicra wé synd ofsette quanto graviore tumultu cogitationum carnalium premimur, Scint. 31, 18. Ne flít hé . . . ne sace ne ástyreð . . . þá beóð Godes bearn þá þe gesibsume beóð and sace ne ástyriað . . . Wé ne magon habban þone heofonlican éþel búton wé fram eallum sacum orsorge beón, O. E. Hml. i. 302, 1-8. I a. rebuke, chiding :-- Mid openre sace beón gehǽled aperta objurgatione sanari, Scint. 115, 16. v. and- (?), ge- (?), weorold-sacu.
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.