Of or pertaining to the philosophy or methods of Aristotle, or to his followers.

(anatomy) Relating to the neck and the back

(virology) Initialism of simian immunodeficiency virus. / (virology) Initialism of swine influenza virus, usually Influenza A virus. / (countable) Initialism of special immigrant visa.

Capable of being knotted, or tied in a knot.