thoroughgoing (adj.)

c. 1300, adjectival use of Old English þuruh (adv.) "from end to end, from side to side," stressed variant of þurh (adv., prep.); see through. Related: thoroughly; thoroughness.

"a moving" in any way, c. 1300, verbal noun from go (v.). The Old English verbal noun was gang "a going, journey; passage, course" (see gang (n.)). Meaning "condition of a road or route for travel" is from 1848, American English; hence to go while the going is good (1907). Going to "be about to" is from late 15c. Goings-on "(questionable) proceedings" attested from 1775.