(1) A term used for a special kind of sale or exchange. According to the Hidayah, bai’u ‘s-sarf, or ; sarf sale, means a pure sale, of which the articles opposed to each other in exchange are both representatives of price, as gold for gold or silver for silver. (See Hamilton’s Hidayah, vol. ii. p. 551.)
2. That part of grammar which relates to the declining of nouns and the conjugating of verbs.
Based on Hughes, Dictionary of Islam