A subject; a tributary.
"Ditionary" is a word that looks like it is mis-spelled, but which is spelled correctly.
I do not fret over spelling or grammar in the context of interpersonal communications. I lack the mental invective for peeves. Still, for the sake of provoking a reaction I might throw this word into a correspondence some day soon.
I became sensitive to the use of "is" and "are" when used in reference to collective nouns when I heard someone say that something would happen "when your dues is paid." Someone attempted to correct the speaker, but he was prepared with a grammar book to demonstrate that "dues" is a collective noun that represents a singular thing. It was an interesting lesson (from a high school Latin teacher) thrown into a seemingly casual conversation. I think this discussion led to talk of "news" being a similar noun, one singular word comprising an array of mental objects but which sounds like it should be plural because it ends in an S.