To be in contact or connection with.
To extend an algebraic object (e.g. a field, a ring, etc.) by adding to it (an element not belonging to it) and all finite power series of (the element).
To associate intimately with; to be close to.
To be similar to, to be almost the same as.
To be adjacent to
A person living on adjacent or nearby land; a person situated adjacently or nearby; anything (of the same type of thing as the subject) in an adjacent or nearby position.
One who is near in sympathy or confidence.
A fellow human being.