1) Lifting freeweights, origianally all made of cast iron. Some are now plastic.

2) Arnold movie about the first definition.
"Can't go out tonight, I'll be pumping iron at home."

"Have you ever seen pumping iron?"
by Gumba Gumba April 14, 2004
Get the mug
Get a pumping iron mug for your mom Beatrix.
To lift weights; to engage in weight or strength training. To work out.
Hot chick at the gym: "OMG! You are so buff!!"
Buff Guy: "Ya babe, I pump iron."
by Gavi120 June 08, 2010
Get the mug
Get a Pump Iron mug for your dog Zora.
"I had to change my sheets because I was pumping iron with Sara last night"
by Quawmfpt January 07, 2015
Get the mug
Get a Pumping Iron mug for your friend Bob.