To mediate, to be an intermediate.
To arrange, in the manner of a broker.
Being between two extremes, or in the middle of a range.
Any substance formed as part of a series of chemical reactions that is not the end-product.
An intermediary.
Anything in an intermediate position.
Strange, and mysteriously unsettling (as if supernatural); weird.
Careless.
Something that is simultaneously familiar and strange, typically leading to feelings of discomfort.