He explained the banking system in warm and friendly tones and with a candor and thoroughness Hoover had never attempted.
I can report that the thoroughness of the yin-yang between their personalities is inherently amusing.
late 15c., 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 (c.1300).