Technically, fiqh is defined as:

مَعْرِفَةُ الْأَحْكَامِ الشَّرْعِيَّةِ الْعَمَلِيَّةِ بِأَدِلَّتِهَا التَّفْصِيْلِيَّةِ

“Knowledge of the practical Shari’ah rulings with their detailed evidences.”

Muhammad b. Salih al-‘Uthaymin, Sharh al-Usul min ‘Ilm al-Usul, (Alexandria: Dar al-Basirah, 1422), 23.