Online English Dictionary

"Noun"

a frame with small balls which slide along wires. It is used as a tool or toy for counting.‹ WORD ORIGINŠ WORD ORIGIN abacus late Middle English (denoting a board strewn with sand on which to draw figures): from Latin, from Greek abax, abak- slab, drawing board, of Semitic origin; probably related to Hebrew 'āḇāq dust.