• The representation of chords by figures placed under the base; figured bass; basso continuo; -- sometimes used as synonymous with harmony.
Thor'ough bass` (Mus.) The representation of chords by figures placed under the base; figured bass; basso continuo; -- sometimes used as synonymous with harmony . 
A thorough bass is a bass which throughout a piece of music has the harmonies indicated by figures according to the intervals above it. An absence of a figure implied a common chord, 6 a first intervention. The thorough bass was probably invented in the 16th century and composers of the new monodic school found it a convenient kind of shorthand. Ac...
[n] - a bass part written out in full and accompanied by figures for successive chords
see basso continuo, figured bass.