A tinghamut was a spherical Vulcan children's toy.
It was the name that Worf gave to a polaron emitter that was knocked out of Odo's hand during their infiltration of a feast for those Klingons about to be inducted into the Order of the Bat'leth in 2373. Worf and Odo claimed that the "toy" was taken for "his son" from the Archanis sector, invaded by the Klingon Empire a few weeks before. (DS9: "Apocalypse Rising")
According to the script, this object's name was pronounced as "TING-ha-mut". [1]