a. Characterized by sharp quick thought; bright. See Synonyms at intelligent.
b. Amusingly clever; witty: a smart quip; a lively, smart conversation.
c. Impertinent; insolent: Thats enough of your smart talk.
2. Energetic or quick in movement: a smart pace.
3. Canny and shrewd in dealings with others: a smart negotiator.
4. Fashionable; elegant: a smart suit; a smart restaurant; the smart set. See Synonyms at fashionable.
5.
a. Capable of making adjustments that resemble human decisions, especially in response to changing circumstances: smart missiles.
b. Manufactured to regulate the amount of light transmitted in response to varying light conditions or to an electronic sensor or control unit: smart windows.
6. New England & Southern U.S. Accomplished; talented: Hes a right smart ball player.
intr.v.smart·ed, smart·ing, smarts
1.
a. To cause a sharp, usually superficial, stinging pain: The slap delivered to my face smarted.
b. To be the location of such a pain: The incision on my leg smarts.
c. To feel such a pain.
2. To suffer acutely, as from mental distress, wounded feelings, or remorse: No creature smarts so little as a fool(Alexander Pope).
3. To suffer or pay a heavy penalty.
n.
1. Sharp mental or physical pain. See Synonyms at pain.
2. smartsSlang Intelligence; expertise: a reporter with a lot of smarts.
Phrasal Verb:
smart offInformal
To speak or act impertinently.
Idiom:
right smartNew England & Southern U.S.
A lot; a considerable amount: He did right smart of the work himself.
[Middle English, stinging, keen, alert, from Old English smeart, causing pain.]
smartly adv.
smartness n.
Regional Note: Smart is a word that has diverged considerably from its original meaning of stinging, sharp, as in a smart blow. The standard meaning of clever, intelligent, probably picks up on the original semantic element of vigor or quick movement. Smart has taken on other senses as a regionalism. In New England and in the South smart can mean accomplished, talented. The phrase right smart can even be used as a noun meaning a considerable number or amount: We have read right smart of that book (Catherine C. Hopley).
smart /smrt/ adj.-er, -est1 able to think well, intelligent: His son is a very smart boy; he is first in his class.2 somewhat rude: The child made a smart remark to her father, so she was sent to bed without dinner.3 fashionable and neat: He wore a smart suit with new shoes. v. [I] 1 to be physically painful, to hurt: Putting alcohol on a cut smarts, but it cleans the dirt out.2 to be emotionally painful: Yesterday you said I was too fat, and the remark still smarts.
rt/ adj. -er, -est 1 able to think well, intelligent: His son is a very smart boy; he is first in his class. 2 somewhat rude: The child made a smart remark to her father, so she was sent to bed without dinner. 3 fashionable and neat: He wore a smart suit with new shoes. 
v. [I] 1 to be physically painful, to hurt: Putting alcohol on a cut smarts, but it cleans the dirt out. 2 to be emotionally painful: Yesterday you said I was too fat, and the remark still smarts. 
ly adv.