(historical) A descendent of the Old East Slavic language, a language used in the 15th to 18th centuries in the Grand Duchy of Lithuania and Cossack state, ancestor of Belarusian, Rusyn, and Ukrain...

(virology) Abbreviation of adenovirus.

(anatomy) A flagellated excretory cell, part of the protonephridium of certain larval animals.

Toward or facing the base; away from the apex.