Final answer:
The antonym for 'innocuous' is 'harmful' or 'dangerous'.
Step-by-step explanation:
The antonym for the term 'innocuous' is unequivocally 'harmful' or 'dangerous.' While 'innocuous' denotes a lack of harm or danger, its antonyms accentuate the potential for adverse consequences or negative impact. When describing substances, actions, or situations as harmful, it implies the capacity to cause damage, injury, or distress. Similarly, 'dangerous' signifies an inherent risk or potential harm. This lexical juxtaposition underscores the critical dichotomy between harmlessness and peril, providing a clear linguistic contrast that aids in articulating the degree of risk or threat associated with various elements, be they substances, activities, or circumstances.