level (n.) Look up level at Dictionary.com
mid-14c., from O.Fr. livel, from L. libella "a balance, level," dim. of libra "balance, scale, unit of weight." The adj. is 1559, from the noun. The verb in the slang sense of "tell the truth" is from 1920. Cognate Sp. nivel, Mod.Fr. niveau are from the same source but altered by dissimilation.