There are several words or phrases that can be used as synonyms for the phrase "first editions." One common alternative is "initial printings," which refers to the first batch of a book that is published. Another option is "1st print runs," which is similar in meaning. "Original releases" is another phrase that can be used in place of "first editions." Additionally, "prototype editions," "early impressions," or "incipient impressions" can also be used to describe the initial publication of a book. Regardless of which term is used, the meaning is the same: the first version of a book that is printed and distributed to the public.