The word "apace" is one of the synonyms for the word "apas." It means "quickly" or "swiftly." Other synonyms include "hastily," "promptly," "expeditiously," "briskly," and "speedily." These words can be used interchangeably with "apas" in sentences such as, "He completed the task apas," or "She ran to the store apace." Alternately, you could use phrases like "with haste" or "in a hurry" as synonyms for "apas." The important thing is to choose the word or phrase that best fits the context of the sentence and conveys the intended meaning.