Lác-sang
Bosworth & Toller Anglo-Saxon Old English Dictionary - lác-sang
According to the Old English Dictionary:
es;
- lác-sang
- m. A song made when offering(?) :-- Lácsang (MS. lane sang) offertorium, Ælfc. Gl. 34; Som. 62, 62; Wrt. Voc. 28, 41. lac-sang