"Principally" is an adverb that means "mainly" or "chiefly". Here are some synonyms for "principally" that you can use to vary your language and writing style: primarily, predominantly, chiefly, largely, mainly, mainly, mostly, essentially, essentially, basically, fundamentally, in essence, principally. These words can help you avoid repetition and keep your writing more interesting. However, be careful not to overuse them, as too many synonyms can make your writing sound awkward or forced. Always make sure to choose the best word for the context of your sentence to convey your message clearly and concisely.