These words have a common meaning of "too much," "more than is required or needed," "excessive": "The speaker's response to the question was redundant (or superfluous or prolix)." Superfluous, derived from Latin terms meaning "overflow," is applicable to anything that is excessive, but redundant and prolix are usually applied to speech and writing. Specifically, redundant refers to unnecessary repetition in expressing ideas, that is, wordiness: "His speaking style is slow and boring, largely because it is so redundant." Prolix, from a Latin word meaning "long," applies to anything, especially speech and writing, that is not necessarily repetitious but is extended to great, tedious, and unnecessary length. Words related to prolix are protracted, verbose, and prolonged. Approximate synonyms for redundant are repetitive, tautological, and pleonastic. Instead of superfluous, occasionally say or write excessive, extra, extravagant, immoderate, and disproportionate.
Dictionary of problem words and expressions. Harry Shaw. 1975.