Final answer:
Nonverbal communication is the term for communication without words, and it encompasses gestures, body language, and facial expressions, all of which can differ by culture.
Step-by-step explanation:
The term that best defines communication without words, including gestures, posture, facial expression, eye contact, voice quality, intonation, and attire, is b) Nonverbal communication. Nonverbal communication is heavily reliant on cultural norms and can vary greatly across different societies. It is symbolic and often includes facial expressions, various forms of body language, and even the tone or quality of voice, which is a component of what is known as paralanguage.
While a smile may generally convey happiness, other gestures like a thumbs-up can have contradictory meanings in different regions. Similarly, body language such as a wave of the hand or a wink can convey a multitude of meanings depending on the situation and cultural context.