Hebetudinous is not a term that is commonly used in everyday language. However, there are several synonyms that can be used to convey a similar meaning. One such synonym is "dull-witted," which implies a lack of intelligence or mental sharpness. Another synonym is "lethargic," which suggests a state of being sluggish or unenergetic. "Listless" is another synonym that describes a lack of interest or enthusiasm. "Sluggish," "unresponsive," and "indolent" are also useful synonyms for hebetudinous. All of these terms can be used to describe someone or something that is slow, dull, or lethargic in nature.