Real Dictionary

smart
adjective: Smart people and things are pleasantly neat and clean in appearance.

Smart in American English
a smarting sensation, pain or distress
causing sharp or stinging pain
Christopher1722-71; Eng. poet
to cause sharp, stinging pain, as a slap
to cause to smart
adjective: quick or prompt in action, as persons
adverb: in a smart manner; smartly
intransitive verb: to be a source of sharp, local, and usually superficial pain, as a wound
noun: a sharp local pain, usually superficial, as from a wound, blow, or sting
transitive verb: to cause a sharp pain to or in

smart in British English
to feel, cause, or be the source of a sharp stinging physical pain or keen mental distress
acronym for: specific, measurable, achievable, realistic, and timely: criteria used in business to devise an employee's performance targets
adjective: astute, as in business; clever or bright
adverb: in a smart manner
noun: a stinging pain or feeling
noun: Christopher. 1722–71, British poet, author of A Song to David (1763) and Jubilate Agno (written 1758–63, published 1939). He was confined (1756–63) for religious mania and died in a debtors' prison