1 A table or tray strewn with sand, anciently used for drawing, calculating, etc. [Obs.]
2 A calculating table or frame; an instrument for performing arithmetical calculations by balls sliding on wires, or counters in grooves, the lowest line representing units, the second line, tens, etc. It is still employed in China.
4 A board, tray, or table, divided into perforated compartments, for holding cups, bottles, or the like; a kind of cupboard, buffet, or sideboard. Abacus harmonicus (Mus.), an ancient diagram showing the structure and disposition of the keys of an instrument. Crabb.