IPA: /hɛbəˈtjuːdɪnəs/
KK: /hɛbəˈtjuːdɪnəs/
Showing a lack of mental sharpness or quickness; being slow to think or respond.
After a long day at work, I felt hebetudinous and struggled to concentrate on my reading.
Comparative: more hebetudinous
Superlative: most hebetudinous
Hebetudinous is formed from "hebetude" (from Latin "hebetudo", meaning dullness or bluntness) and the suffix "-inous" (meaning having the quality of). The word describes something that has the quality of dullness or lack of sharpness.
Think of 'hebetude' meaning dullness, and remember that 'hebetudinous' refers to something that has the quality of being dull.
No commonly confused words.