Final answer:
A power necessary for carrying out a specific grant of power that is not mentioned in the Constitution is called an implied power. These powers stem from the 'necessary and proper clause' of Article I, Section 8, which allows Congress to enact laws deemed necessary to execute its enumerated powers.
Step-by-step explanation:
The power not specifically mentioned in the Constitution but necessary if another specific grant of power is to be carried out is called a(n) implied power. These powers are not explicitly stated but are inferred as necessary to fulfill the functions of the national government. An example of this can be seen in the government's power to regulate interstate commerce which then extends to prohibiting racial discrimination on transportation services because it relates to commerce.
Implied powers find their authority in the Constitution, emanating from the "necessary and proper clause" of Article I, Section 8. This clause allows Congress to execute its enumerated powers effectively by providing the flexibility to determine what is necessary and proper. The concept of implied powers was instituted to ensure that the government could adapt and enact measures that are crucial for the nation to function, even if they are not explicitly detailed within the written text of the Constitution.