Thick-wittedness refers to a lack of intelligence or understanding, and there are several synonyms for this term. The word "stupidity" is a straightforward replacement for thick-wittedness, meaning a lack of intelligence or common sense. "Ignorance" is another synonym, implying a lack of knowledge or understanding. "Dullness" suggests a lack of mental sharpness or quickness, while "foolishness" connotes a lack of good judgment or common sense. "Dimness" is a synonym for thick-wittedness that implies a lack of mental clarity or brightness. Whatever word is used, thick-wittedness implies a lack of intelligence that can hinder success and personal growth.