Ciardi was born in Boston's Little Italy. He attended Bates College, Tufts College and the University of Michigan. After serving in the Army Air Corps during World War II, he taught at the University of Kansas City, Harvard, and finally at Rutgers. In 1961, he left his tenured position for an independent career.
Ciardi was well known for his poetry for adults and children and his English translations of Dante Alighieri's great works. He worked with Isaac Asimov on collections of limericks.
As an etymologist, he is known for a three-volume Browser's Dictionary and his broadcasts on National Public Radio, both as host of A Word in Your Ear and as a commentator for Morning Edition and Weekend Edition. Etymologies and commentary on words such daisy, demijohn, jimmies (the sprinkles on doughnuts and ice cream), gerrymander, glitch, snafu, cretin, and baseball, among others, are available from the archives of NPR's website.
He died on Easter Sunday, 1986 of a heart attack in New Jersey, but not before composing his own epitaph:
Here, time concurring (and it does);
Lies Ciardi. If no kingdom come,
A kingdom was. Such as it was
This one beside it is a slum.
A partial bibliography: