The word "changefully" refers to a continuous change or variation in something. There are various synonyms that can be used to communicate the same meaning, including fluctuatingly, variably, mutably, mercurially, and transitionally. Fluctuatingly refers to something that is constantly changing, up and down, while variably is used to describe something that is subject to change. Mutably means something that is capable of being changed, while mercurially refers to something that changes suddenly and unpredictably. Transitionally is used to describe a gradual change from one state to another. All of these synonyms can be used interchangeably to convey the same idea of continuous change in a particular thing or situation.