1. the period in the history of humankind, following the Stone Age and the Bronze Age, marked by the use of implements and weapons made of iron.
2. (l.c.) Class. Myth.the present age, following the bronze age; the last and worst of the four ages of the human race, characterized by danger, corruption, and toil.
3. (l.c.) any age or period of degeneracy or wickedness.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.