The word "postolivary" refers to a part of the brain located near the olivary nucleus. The spelling of this word can be explained using the IPA phonetic transcription, which would be /pəʊstɒlɪvəri/. The "post-" prefix means "after" or "behind", while "olivary" refers to the olive-shaped structure in the brain. The "-ary" suffix means "pertaining to". Therefore, "postolivary" means "pertaining to the area behind the olivary nucleus in the brain".
Situated posterior to the oliva.
A practical medical dictionary. By Stedman, Thomas Lathrop. Published 1920.
There is no known word "postolivary" in the English language, and there is no etymology available for a word without a recognized lexical entry. It is possible that the word is a neologism or a misspelling.