Squarefree vs. Nontrivial — What's the Difference?

(mathematics) Not divisible by a nontrivial square.

Not trivial; of some importance.

(Mathematics) Of, relating to, or being an expression in which at least one variable is not equal to zero.

Not trivial.

(mathematics) Not obvious or easy to prove; not self-evident.

(mathematics) Not being of the simplest kind; not being empty or a singleton.

(computing) Needing significant computing power to solve; intractable.