thorough

Thorough is an adjective describing something performed with great care and complete coverage of all parts or aspects. A thorough effort aims to leave nothing out, attending to details and ensuring accuracy, completeness, and reliability. The quality implied is depth and meticulousness, rather than speed or surface-level treatment. In common usage, it is applied to tasks such as inspections, investigations, cleaning, reviews, and analyses. The corresponding adverb is thoroughly.

Usage and nuance: Thorough signifies both scope and rigor. It suggests that a process has been carried out from start to finish with careful consideration of all relevant elements. It is often contrasted with superficial, partial, or cursory approaches, which may be quick but miss important details. Synonyms include comprehensive, exhaustive, complete, meticulous, and rigorous; antonyms include superficial, incomplete, and partial. In some contexts, thorough can carry a formal or professional tone, as in a thorough safety audit or a thorough legal review.

Etymology and history: The word traces to Middle English thorow or thorowly, from the Old English through or through-and-through ideas connected to exhaustiveness. Over time, the sense of “looking at all parts” or “covering all aspects” became central to its meaning, extending to various domains where precision and completeness are valued.

See also: thoroughgoing, thoroughly (adverb). Applications span professional fields such as science, medicine, engineering, law, and education, as well as everyday tasks where careful and complete attention is required.