What is the grammatical term for "further" in relation to other measurements?

The term "further" serves as a comparative form when it is used in relation to other measurements. In English grammar, comparatives are used to compare differences between the two objects they modify (usually adjectives and adverbs). "Further" is used to indicate a greater distance or degree in relation to another item, which is the essence of comparative adjectives or adverbs. For example, if one distance is 5 miles and another is 10 miles, one might say the latter is "further" than the former.

The positive form describes a single quality without comparison, while the superlative form indicates the highest degree among three or more subjects. Adverbial refers to the function that a word or phrase performs rather than its comparative nature in this context. Thus, the classification of "further" as a comparative term is accurate based on its grammatical function when used to make comparisons.