One who bereavs or deprives; something or someone that causes loss or grief (archaic/rare).
From 'bereave' + '-er' (agent noun suffix meaning 'one who does'). Though grammatically regular, this word is rarely used in modern English.
While we'd never normally call Death itself a 'bereaver,' poets sometimes do—it's one of those archaic words that suddenly pops up in gothic literature to sound more ominous and old-fashioned!
Complete word intelligence in one call. Free tier — 50 lookups/day.