Final answer:
The term for meaningless hand and arm movements in speech is 'nonverbal communication,' specifically 'gesticulation'. These gestures are often spontaneous and contribute to the emotional tone of the speaker's message.
Step-by-step explanation:
The term for hand and arm movements in speech that don't have meaning, such as waving arms up and down, is nonverbal communication. These movements are often symbolic and can include gestures like smiles or winks, which can convey a variety of messages depending on the cultural context and the situation. However, certain movements that are done without specific intent or meaning during a conversation could be considered gesticulation, which is a form of nonverbal communication characterized by spontaneous movements that accompany speech but do not have a direct translation to specific words or phrases.
For example, when a person is excited or emphasizing a point while speaking, they may gesture broadly with their hands and arms. While these actions do not have a specific meaning or direct communication intent, they can still contribute to the overall impression and emotional tone of the speaker's message.