Quadruply is an adverb meaning four times as much, or done in a fourfold manner. There are several synonyms to the word quadruply, including four times, fourfold, quadruple, and four-way. Variations in their usage make the sentences more interactive and lend some delicacy to the language. For instance, you can say, "She increased her investment quadruply," or "Her profits quadrupled after the merger." Both sentences mean the same thing, but the second one sounds more affirmative. In conclusion, synonyms like four times, fourfold, four-way, and quadruple can be used in lieu of quadruply, providing a lively, dynamic and more personalized ensemble to your sentences.