In a decadal manner / With respect to decades

plural of decadent

plural of decad

Archaic form of decade (“period of ten years”). / Archaic form of decade (“group of ten”). / (music) A group of ten notes from which the consonant triads may be constructed

plural of decadency

plural of decadeful

The amount that fills or is produced in a decade.

(music) The modification of a decad, typically to obtain a new series of consonant triads

plural of cosmological decade

(euphemistic, humorous) Decades old.