What is the smallest meaningful linguistic unit that cannot be divided further?

The smallest meaningful linguistic unit that cannot be divided further is indeed a morpheme. Morphemes are the building blocks of language and can either be free morphemes, which can stand alone as words (like 'cat' or 'run'), or bound morphemes, which cannot stand alone and must be attached to other morphemes to convey meaning (like the prefixes 'un-' or the suffixes '-ing').

Morphemes are critical in understanding the structure of words and how they convey meaning. For instance, the word 'running' can be broken down into two morphemes: 'run' (the root or base word) and '-ing' (a suffix indicating the present continuous tense). This exemplifies how morphemes work together to form more complex meanings in language.

In contrast, a word itself is a broader concept and can consist of one or more morphemes, therefore not capturing the essence of the smallest unit of meaning. Phonemes, on the other hand, are the smallest units of sound that can distinguish meaning but do not themselves carry meaning. Lastly, a morpheme with no meaning would not fit the definition since it fails to function as a meaningful unit of language. Hence,