Is it necessary to wait until the discharge of madhy (pre-seminal fluid) stops before praying, or is it sufficient to wash the penis, perform wudu (ablution), and pray, and what is the definition of a mithaa’ (a man who frequently discharges madhy)?

If madhy (pre-seminal fluid) exits, wait until it stops, then perform wudu' (ablution) and pray, even if alone. However, if you are certain that the prayer time will end before the madhy stops, then you must wash the penis, protect it with a cloth, then perform wudu' and pray. What exits after that will not harm you. A man who frequently experiences madhy is someone from whom madhy exits often, and he is not necessarily considered to have urinary incontinence (sils).