"‘Urf": a term that collectively refers to all the things that a given society knows and recognizes as good. Original meaning: what is "ma‘rūf", i.e. known and recognized, of good and benevolent deeds. Other meanings: what is common and known among people.
"Ikhtilāf": dispute, disagreement, contradiction, reversal. Opposite: agreement. It is derived from "khilāfah", which means: succession and replacement of something by another. Other meanings: variation, change, dispersion.
"Dalīl" (pl. adillah): what leads to something destined. It is derived from "tadlīl", which means indicating something with a sign. Other meanings: sign, supplementary evidence, guide, origin.
Proofs that are established through speculation, opinion, and personal reasoning.
Non-obligation of man to fulfill religious obligations and financial duties until evidence from the Shariah is established to this effect.
What has been transmitted from the Companions of the Prophet, may Allah's peace and blessings be upon him, of independent reasoning in one of the issues of the religion.
In analogy, it refers to the basic rule, as opposed to the subsidiary rule.
Anything that is approved by reason or known through human intellect.
The laws of previous heavenly-inspired religions that were authentically transmitted to us, Muslims.
Examining particular instances, or majority of such instances, to apply their ruling to a general instance that includes them.
Sources of Islamic legislation that are contested by the scholars, such as the sayings of the Companions, etc.