adjective
(archaic or regional, Yorkshire) Neat, smartly dressed, attractive.
noun
(uncountable) Attractiveness or charm in dress, appearance, or manner.
(countable, archaic, slang) A well-dressed man; a swell.
(countable, commerce, slang) A bonus or other remuneration, given for reaching a sales goal or promoting the goods of a particular manufacturer. Originally from textile retailing, a percentage given for selling off surplus or out-of-fashion stock, of which the sales person could offer part as a discount to a customer.
(countable, colloquial, Jamaica) Alternative form of spliff (“hand-rolled marijuana cigarette”).
verb
(transitive, informal) (usually with up or out) To make spiffy (attractive, polished, or up-to-date)
(transitive, commerce, slang) To reward (a salesperson) with a spiff or bonus.
(transitive, commerce, slang) To attach a spiff or bonus to the selling of (a product)