Syllable division derived from spelling — this word is not in the pronouncing dictionary, so no phonetic transcription is shown rather than a guessed one.
thoroughgoing is an adjective meaning "performed comprehensively and completely; not superficial or partial". It carries 2 recorded senses.
performed comprehensively and completely; not superficial or partial
“an exhaustive study”
“made a thorough search”
“thoroughgoing research”
without qualification; used informally as (often pejorative) intensifiers
“an arrant fool”
“a complete coward”
“a consummate fool”
“a double-dyed villain”
“gross negligence”
“a perfect idiot”
“pure folly”
“what a sodding mess”
“stark staring mad”
“a thorough nuisance”
“a thoroughgoing villain”
“utter nonsense”
“the unadulterated truth”
Definitions, synonyms and semantic relations for thoroughgoing come from Princeton University’s WordNet. Commonness is measured against a corpus of everyday English. Full sources and licences.