decadal

Concise Oxford English Dictionary © 2008 Oxford University Press:
decade /ˈdɛkeɪd, dɪˈkeɪd/

▶noun

• 1 a period of ten years.

• 2 a set or group of ten.

  ■ a range of electrical resistances or other quantities spanning from one to ten times a base value.

• 3 each of the five divisions of each chapter of the rosary.

– derivatives
decadal adjective.

– origin ME: via OFr. and late L. from Gk deka ‘ten’.

usage: The second pronunciation, with the stress on -cade (sounds like decayed), is disapproved of by some traditionalists. However, it is now widely regarded as a standard alternative.