المعنى الاصطلاحي :

A science whereby the general proofs of the Islamic jurisprudence are derived, and the manner of applying them is known, along with knowing the state and description of those to whom such proofs are applicable.

الشرح المختصر :

"Usool al-Fiqh" (fundamentals of Islamic jurisprudence) is a science that discusses three aspects: 1. The proofs in general: These are the general rules which are derived from the Qur’an, the Sunnah, and "ijmā‘" (consensus). For example, a command indicates obligation, and a prevention implies prohibition. So, detailed evidence, such as the Qur’an, is not included here. They are mentioned in the context of giving examples only. 2. What leads to the proofs: What is said about these proofs; the characteristics of each type of proof; and how these types are connected, arranged, given priority over each other, and opposed to each other. 3. Knowing how to employ the proofs and the characteristics of those to whom the proofs apply: This is done by studying their words and their indications, including the general, the specific, the absolute, the restricted, the abrogated, etc. "Fiqh" (jurisprudence) means knowing the Shariah rulings that are established through "ijtihād" (independent reasoning), such as the obligatory, the recommended, the disliked, the forbidden, the permissible, the valid, and the invalid.