smart vs shrewd

smart is a noun but shrewd is not a noun.

Word	Noun	Adjective	Verb	Adverb
smart	Yes	Yes	Yes	No
shrewd	No	Yes	No	No

smart (noun)	shrewd (noun)
a kind of pain such as that caused by a wound or a burn or a sore

smart (adjective)	shrewd (adjective)
showing mental alertness and calculation and resourcefulness	acting with a specific goal
capable of independent and apparently intelligent action	marked by practical hardheaded intelligence
quick and brisk
improperly forward or bold
characterized by quickness and ease in learning
painfully severe
elegant and stylish

smart (verb)	shrewd (verb)
be the source of pain