While John McCarthy and other sources offer valuable definitions, none of them fully encompass the qualities that make an entity not just "clever" but genuinely intelligent in the way humans are: the ability for abstract thinking, problem-solving, emotional understanding, and self-awareness.
If we accept the idea that any computer performing a task indistinguishable from a human is "intelligent," then we'd also have to concede that simple calculators are intelligent because they perform arithmetic as accurately as a human mathematician. This reduces the concept of intelligence to mere task performance, diluting its complexity and richness.
By the same logic, a wind-up toy that mimics animal movement would be "intelligent" because it performs a task—walking—that in another context, i.e., a living creature, is considered a sign of basic intelligence. Clearly, this broad classification would lead to absurd results