thoroughly

Thoroughly is an adverb that means to a complete or highly careful degree. It describes actions carried out with depth, care, and attention to detail. It can modify verbs, adjectives, or other adverbs, as in “They inspected the premises thoroughly,” “I’m thoroughly convinced,” and “The report is thoroughly documented.”

Etymology and form: The adverb is formed from the adjective thorough, which traces to Old English and earlier Germanic roots related to the idea of going through something. The suffix -ly was added in Middle English to produce the adverb. The spelling throughly is generally considered incorrect or archaic in modern usage.

Usage notes: Thoroughly often precedes the word it modifies, including adjectives (thoroughly modern, thoroughly trained) and verb phrases (thoroughly investigated, thoroughly enjoyed). It emphasizes completeness, rigor, or depth, rather than merely a mild degree. It can overlap with synonyms such as completely, entirely, or rigorously, but its nuance tends toward meticulousness and thoroughness rather than sheer extent alone.

Common cautions: Do not confuse thoroughly with throughly, a nonstandard spelling. While thoroughly is versatile, it is most natural when signaling carefulness, depth, or exhaustive examination. In formal writing, it remains a precise way to convey that a task was performed with all aspects considered and completed.