Altogether or all together ? English Grammar Today a reference to written and spoken English grammar and usage Cambridge Dictionary.Synonyms for all together at Thesaurus.com with free online thesaurus, antonyms, and definitions. Find descriptive alternatives for all together..Define all together. all together synonyms, all together pronunciation, all together translation, English dictionary definition of all together. Adv. . all together all at the same time “Let’s say `Yes!’ all at once” all at once . all together used of a group whose members acted or were acted .All together means “everyone together” or “everything together.” It’s often said that the whole isn’t necessarily the sum of its parts. That maxim applies when you turn “every day” into “everyday,” and it’s the same when you turn all together into altogetheryou get something completely different..