Sídung

According to the Old English Dictionary:

e ;

sídung

f. An extension, augmentation :--Ymbe ðises bissextus gefyl-lednysse wé wyllaþ rúmlícor iungum cnihtum geopenian . . . ðæt hig syððan his sýdunge óðrum gecýðon . . . De augmentatione bissexti, (then follows the promised account), Anglia viii. 306, 16. sidung