Coefficient: In a polynomial expression, coefficients are numerical constants multiplied by variables raised to various powers. For example, in $3x^2$, 3 is the coefficient.
Degree: As mentioned earlier, degree refers to the highest power of a variable in a polynomial expression. In terms of individual terms within an expression, it indicates their level or magnitude compared to others.
Leading term: The leading term is similar to the seventh-degree term but specifically refers to the highest degree (power) term in an entire polynomial expression rather than just one individual term within it.