المعنى الاصطلاحي :

The person upon whom the validity of the marriage contract is contingent, such as father, his agent, or the like.

الشرح المختصر :

"Wali" (guardian) is the one upon whom the validity of the marriage contract is contingent; i.e. it is invalid without his presence/consent. "Wali" may be the (bride's) father, his agent, an agnate relative, the owner or manumitter (of a bonds-woman), or the Muslim ruler (of a free woman). One definition given to the "wali" is: an adult sane male who is entitled to inherit (from the bride). The general meaning of "wali" is: a person who is legally responsible for another person; such as the father in relation to his young or insane child, or the judge and the imam.

التعريف اللغوي المختصر :

"Wali": guardian, patron. Derived from "waly", which means closeness. Other meanings: ally.