What is an honest basis? In a comment to this question, the commentator stated that 
"the monomials form an honest basis for your vector space".
To be honest, I never heard of that. Is this something elementary?

This was not a term of art, but rather an attempt at emphasis. The monomials form a basis for the vector space in the usual sense (every vector is a linear combination of elements of the basis in a unique way), as opposed to, for instance, a Hilbert basis (whose linear span is not necessarily equal to the entire space). 
(Reminds me of something that happened when I was taking Measure Theory in my final undergraduate year; the professor had his own very good notes, with a set of exercises. One of the problems asked us to prove that a function that satisfied a certain property "is automatically continuous"; we couldn't figure out what the definition of "automatically continuous" was, and asked the professor the next lecture. Of course, he meant that such a function would necessarily be continuous...)
