The Latin word is derived from ancient Greek  (abax) which means something without a base, and colloquially, any piece of rectangular material.
ðə lˈætɪn wˈɜːd ɪz dᵻɹˈaɪvd fɹʌm ˈeɪntʃənt ɡɹˈiːk ɐbˈæks wˌɪtʃ mˈiːnz sˈʌmθɪŋ wɪðˌaʊt ɐ bˈeɪs, ænd kəlˈoʊkwɪəli, ˌɛni pˈiːs ʌv ɹɛktˈæŋɡjʊlɚ mətˈɪɹiəl.