English Reference
adjective

thorough

adj.
US /ˈθɝoʊ/ UK /θˈʌɹɐ/ thor·ough

  1. 01 B2 Upper Intermediate

    doing something very carefully and making sure you do not miss any details.

    painstaking and meticulous; ensuring that every detail is addressed or examined.

    Simple

    The doctor gave him a thorough examination to find the cause of his pain.

    In context

    The researchers conducted a thorough review of the existing literature before proposing their new hypothesis to the board.

    Pitfall
    The police made a through investigation. The police made a thorough investigation.

    Do not confuse 'thorough' (careful) with 'through' (moving from one side to the other).

  2. 02 C1 Advanced Formal

    complete in every way; used to emphasize how total a quality is.

    absolute or utter; used as an intensifier to indicate that a quality is complete.

    Simple

    The party was a thorough success and everyone enjoyed themselves.

    In context

    The collapse of the negotiations was a thorough disappointment for the diplomats who had spent months preparing the draft.

Usage thorough analysis · thorough discussion · thorough investigation

The global ride-hailing giant said it had come to the "difficult decision" after a thorough review of its business.

BBC News· 2 Sept 2026

It gets there most of the time, but it’s nowhere near good enough that I’d trust the results without a thorough double-check.

Ars Technica· 14 Aug 2026
This entry
Level B2 · Upper Intermediate
Frequency Frequent
Updated