One spelling is correct; the other uses the wrong suffix.
Incorrect spelling - "Thoroughely" is not valid English.
"thoroughely" is a common misspelling of "thoroughly". Always use "thoroughly" when referring to the correct word.
Correct spelling - The proper way to spell this word.
"Thoroughly" means fully or completely.
"thoroughly": "Thoroughly" means fully or completely.
This word is commonly used in everyday conversation and writing.
"Correct:" He searched thoroughly.
"Correct:" Explain thoroughly.
"Incorrect:" He searched thoroughely.
"Incorrect:" Explain thoroughely.
A: Thoroughly.
Thoroughly is the correct adverb form and ends in '-ly'. Thoroughely incorrectly alters the suffix and is not accepted in English. Correct spelling ensures clarity and professionalism in formal and instructional writing.