Container with shredded old mail that contains two terms (8)
I believe the answer is:
'container with shredded old mail that contains two terms' is the definition.
Although both the answer and definition are singular nouns, I can't see how one could define the other.
'container with shredded old mail' is the wordplay.
'container' becomes 'bin' (bin is a kind of container).
'with' means one lot of letters go next to another.
'shredded' indicates an anagram.
'old' becomes 'o' (common abbreviation eg in OE for Old English).
'omail' is an anagram of 'omial'.
Can you help me to learn more?
(Other definitions for binomial that I've seen before include "(Of an equation) consisting of two terms - in a limbo (anag)" , "with two names" , "Algebraic expression of two terms linked by + or -" .)