iron group

noun4

1. •
   Any of several groupings of elements that share traits with iron in one way or another.
2. •
   Row 4 (period 4) of the periodic table, or a large subset thereof.
3. •
   A smaller subset thereof comprising iron, cobalt, and nickel.
4. •
   Group 8 of the periodic table, comprising iron, ruthenium, osmium, and hassium.