| Date: | 1400-1500 |
| Origin: | thorough 'through' (11-21 centuries), from through |
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thor‧ough

1 including every possible detail [↪ thoroughly]:
The doctor gave him a thorough check-up.
a thorough and detailed biography
The police investigation was very thorough.
thorough notes of the meeting
The doctor gave him a thorough check-up.
a thorough and detailed biography
The police investigation was very thorough.
thorough notes of the meeting2 [not usually before noun] careful to do things properly so that you avoid mistakes :
The screening of applicants must be thorough.
The screening of applicants must be thorough.3 used to emphasize the bad qualities of someone or something
a thorough pest/nuisance/mess
British English —thoroughness noun [uncountable]
