Definition of thorough-bass:
(adj) :
Painstaking and careful not to miss or omit any detail.
(adj) :
Utter; complete; absolute.
(n) :
(UK, dialect) A furrow between two ridges, to drain off the surface water.
(n) :
(Christianity, historical) A scheme devised in 17th-century England by Thomas Wentworth, 1st Earl of Strafford to establish absolute monarchy in England, involving the appointment of Arminian clergy.