Source : Webster's Revised Unabridged Dictionary (1913)

Alder \Al"der\ ([add]l"d[~e]r), Aller \Al"ler\ ([add]l"l[~e]r),
   a. [From ealra, alra, gen. pl. of AS. eal. The d is
   excrescent.]
   Of all; -- used in composition; as, alderbest, best of all,
   alderwisest, wisest of all. [Obs.] --Chaucer.

Aller \Al"ler\, a. [For ealra, the AS. gen. pl. of eal all.]
   Same as {Alder}, of all. [Obs.] --Chaucer.