Found this heavy, spiked metal disc in the back of a junk drawer. Sharp as needles. No idea what it’s used for?

Frog
While the kenzan is distinctive, there are other spiked objects that might be mistaken for it. Some kitchen tools or gardening implements feature spikes for entirely different purposes, such as meat tenderizers or soil aerators. These items are generally larger, with different spike configurations.
To distinguish a kenzan, look for the densely packed, uniform spikes set into a circular or rectangular base. The spikes should be fine and needle-like, designed specifically for holding stems. If in doubt, consulting with a florist or Ikebana enthusiast can quickly confirm the identity of your spiked disc.