Final answer:
The smallest unit of speech that denotes meaning is a morpheme. It differs from a phoneme, which is a sound without meaning, and a word, which is the smallest stand-alone unit of meaning. Phrases are groups of words that convey concepts but lack a complete predicative structure.
Step-by-step explanation:
The term defined as "the smallest unit of speech that denotes meaning" is a morpheme. Unlike a phoneme, which is a basic sound unit that does not convey meaning on its own, a morpheme can change the meaning of a word when added or altered. For example, adding the morpheme '-s' to the end of 'dog' changes the meaning from singular to plural ('dogs'). A word may consist of one or more morphemes, but is generally considered to be the smallest unit of language that can stand alone and still convey meaning. A phrase, on the other hand, is a group of words that conveys a concept but does not have both a subject and a predicate, and therefore cannot stand alone as a complete sentence. Finally, a phoneme is a sound or set of sounds that can distinguish one word from another in a particular language but does not have inherent meaning by itself.