(1):
(adv.) Thoroughly.
(2):
(adv.) Through.
(3):
(a.) Passing through; as, thorough lights in a house.
(4):
(prep.) Through.
(5):
(n.) A furrow between two ridges, to drain off the surface water.
(6):
(a.) Passing through or to the end; hence, complete; perfect; as, a thorough reformation; thorough work; a thorough translator; a thorough poet.