as thick as a plank Antonyms
able-minded
qualified
read
scholarly
scholastic
sharp-witted
sly
versatile
versed
well-informed
well-read
witty
au courant
well-educated
polymathic
philosophical
pedantic
artful
bookish
cerebral
cognizant
conversant
discriminating
encyclopedic
erudite
lettered
literary
literate
many-sided
omniscient
eggheaded