Octadic is a term that describes something with eight parts or elements. It is a word commonly used in mathematics and science to describe various systems, such as octadic groups, octadic codes, or octadic lattices. However, there are several synonyms for the word 'octadic' that can be used to describe similar systems or elements. Some of the synonyms include octonary, eightfold, octagonal, and octal. These words can be used interchangeably with 'octadic' depending on the context of the sentence and the subject matter being discussed. Regardless of the synonym used, the meaning remains the same; eight parts or elements.