A faqih is a jurist, one trained in fiqh, the discipline of deriving and applying the rulings of Islamic law, and the faqih is the ordinary working scholar of the legal tradition.
The discipline of fiqh
Fiqh is the human understanding and elaboration of the sacred law, the systematic work of deriving concrete rulings from the sources, the Quran, the practice of the Prophet, and the accepted methods of reasoning, and the faqih is the specialist in this discipline, trained in a school of law and competent to expound and apply its rulings. The office is scholarly rather than sacerdotal, since Islam has no ordained clergy, and the faqih standing rests on training and recognition by the community of scholars.
Where the faqih stands
The faqih works within an established school of law and its accumulated body of rulings, and most jurists apply and interpret the settled positions of their school rather than deriving law afresh from the sources, which is the more demanding office of the mujtahid. The faqih may serve as a teacher, a mufti giving legal opinions, or a judge, so the discipline underlies several of the practical legal offices. In the Shia world the term takes on particular weight in the modern doctrine of the guardianship of the jurist, which assigns political authority to a qualified faqih. In its general sense, however, the faqih is simply the trained jurist, the scholar who carries the ordinary work of understanding and applying the sacred law within his tradition.