n A temporary position at an academic institution with limited teaching duties and ample time for research; this may also be called a postdoctoral | postdoc.
n (medicine) A period of supervised, sub-specialty medical training in the United States and Canada that a physician may undertake after completing a specialty training program or residency.
n (Christianity) Spiritual communion with a divine being.
v (transitive) To admit to fellowship, enter into fellowship with; to make feel welcome by showing friendship or building a cordial relationship. (non-gloss definition|Now only in religious use.)
v (intransitive) To join in fellowship; to associate with. (non-gloss definition|Now only in religious use, and chiefly U.S.)