When a child utters the word "mama," it may signify meanings as varied as "There goes Mama," "Come here, Mama," and "You are my Mama." Such single words used by children to express complex meanings are known as .

- Holophrases.

Explanation:

As per the question, the child uses single word like 'mama' to convey various complex meanings like 'Come here, Mama', 'You are my Mama', etc. exemplify that he is using 'holophrases' while learning to speak the language. Such phrases(holophrases) do not possess a grammatical intent but a simple vocalization that the child crams while learning and uses in order to convey his thought through that specific single word. Thus, 'holophrases' is the correct answer.

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