Abacus

Etymology
Entered English circa 16th century. abacus:, abax:; from Greek ἄβαξ: (board covered with sand), possibly from אבק: (dust).

Noun

 * 1)  A table or tray strewn with sand, anciently used for drawing, calculating, etc.
 * 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.
 * I've heard merchants still use an abacus for adding things up in China.
 * 1)  The uppermost member or division of the capital of a column, immediately under the architrave.
 * 2)  A tablet, panel, or compartment in ornamented or mosaic work.
 * 3) A board, tray, or table, divided into perforated compartments, for holding cups, bottles, or the like; a kind of cupboard, buffet, or sideboard.

Derived terms

 * abacus harmonicus

Related terms

 * abacist