Final answer:
The term that describes the dilation or expansion of the bronchus is bronchiectasis. This condition signifies a permanent enlargement of parts of the airways in the lungs different from bronchitis or bronchospasm, which are related but distinct conditions.
Step-by-step explanation:
The word that means dilation or expansion of the bronchus is e. bronchiectasis. Bronchiectasis is a condition where there is permanent enlargement of parts of the airways of the lung. The bronchi are the passageways that allow air to enter and exit the lungs, and in bronchiectasis these passageways become widened.
Bronchitis is an inflammation of the bronchi and bronchospasm refers to the sudden constriction of the muscles in the walls of the bronchioles. It is important to not confuse these terms as they represent different respiratory conditions. To reiterate bronchiectasis specifically refers to the dilation or expansion of the bronchi, making it the correct answer to the question.