Steelie is a slang term used to refer to a type of toy marble made from steel. For those seeking variety in their marble collection, there are a few other terms that are used to describe similar marbles. One such term is "ball bearing," which is derived from the fact that steelies often contain a ball bearing at their core. Other synonyms for steelies include "shooter" or "shooting marble," which refer to the larger size of the marble and its potential for use in a game of marbles. Regardless of which term is used, it is clear that steelies and their synonyms refer to a timeless toy that has been enjoyed by generations.