Existentially is an adverb used to describe something in relation to existence or a person's experience of the world. There are many synonyms for existentially, including fundamentally, essentially, inherently, intrinsically, and essentially. These words all point to something that is crucial to existence or the essence of a person or thing. Additionally, words like personally, subjectively, and individually also capture the experiential aspect of existentially. They describe something that exists in a deeply personal and subjective way. Ultimately, the act of existing is a deeply layered and complex concept, and there are many words that attempt to capture its nuances.