A noun appearing as ᴱN. dagros “slaughter” in Early Noldorin Word-lists of the 1920s based on the verb ᴱN. (n)dag- “to slay” (PE13/141). It also appeared in the contemporaneous Early Qenya Phonology (PE14/66).
Neo-Sindarin: For purposes of Neo-Sindarin, I would update this form to ᴺS. dagras using the later abstract noun suffix -as.
A noun for “slaughter” in the Early Noldorin Word-lists of the 1920s, an elaboration of ᴱN. rhanc “corpse” (PE13/152).