Question 17366
Trinomial (3)...An expression having three terms.

Quintic (5)monomial (1)...An expresion having a single term (monomial) raised to the 5th (quintic) power.

Quartic (4) binomial (2) ... an expression having two terms (binomial) in which the highest power is 4 (quartic).

Cubic (3) polynomial (many terms)...an expression having more than one term (polynomial) in which the highest power is 3 (cubic).
 
The square (2) of a cubic (3) polynomial (many terms)...The square of an  expression having more than one term (polynomial) in which the highest power is 3 (cubic).

This will, hopefully, help you sort things out.