"Giant strides" is an idiom that means making significant progress, usually in a short amount of time. Some synonyms for this expression are "remarkable advances," "significant leaps," "great strides," "momentous progress," "notable gains," "substantial headway," and "impressive advancements." These synonyms can be used interchangeably depending on the context and emphasis of the message. They all convey the idea of making significant steps towards achieving a goal or accomplishing a task. Whether in business, education, or personal development, using these synonyms can add variety and nuance to one's writing or speaking and emphasize the importance of progress and growth.