<p><strong>Verb (used without object)</strong></p><ul><li>to be a source of sharp, local, and usually superficial pain, as a wound.</li><li>to be the cause of a sharp, stinging pain, as an irritating application, a blow, etc.</li><li>to feel a sharp, stinging pain, as in a wound.</li><li>to suffer keenly from wounded feelings: She smarted under their criticism.</li><li>to feel shame or remorse or to suffer in punishment or in return for something.</li></ul><p><strong>Verb (used with object)</strong></p><ul><li>to cause a sharp pain to or in.</li></ul><p><strong>Adjective</strong></p><ul><li>quick or prompt in action, as persons: Synonyms: active, alert, agile, nimble, lively.</li><li>having or showing quick intelligence or ready mental capability: a smart student. Synonyms: adroit, expert, sharp, bright. Antonyms: stupid.</li><li>shrewd or sharp, as a person in dealing with others or as in business dealings: a smart businessman. Synonyms: adept, cunning.</li><li>clever, witty, or readily effective, as a speaker, speech, rejoinder, etc.</li><li>dashingly or impressively neat or trim in appearance, as persons, dress, etc.: Synonyms: showy, pretentious, spruce.</li><li>socially elegant; sophisticated or fashionable: the smart crowd. Synonyms: chic.</li><li>saucy; pert: smart remarks.</li><li>sharply brisk, vigorous, or active: to walk with smart steps. Synonyms: energetic.</li><li>sharply severe, as a blow, stroke, etc.</li><li>sharp or keen: a smart pain. Synonyms: penetrating, poignant.</li><li>(of a machine, system, etc.) equipped with electronic control mechanisms, software programs, etc., and capable of remote, automated, and seemingly intelligent operation: smart copiers; smart weapons; a smart thermostat.</li><li>equipped with microprocessors, as for data processing, internet access, etc. (usually used in combination): a smartphone; a smartwatch.</li><li>having properties that can be changed in response to stimuli or environmental conditions; self-regulating: smart fabrics that respond to temperature or light.</li><li>Older Use: considerable; fairly large.</li></ul><p><strong>Adverb</strong></p><ul><li>in a smart manner; smartly.</li></ul><p><strong>Noun</strong></p><ul><li>a sharp local pain, usually superficial, as from a wound, blow, or sting.</li><li>keen mental suffering, as from wounded feelings, affliction, grievous loss, etc.</li><li>smarts, Slang: intelligence; common sense: He never had the smarts to use his opportunities.</li></ul>