المؤخر
كلمة (المؤخِّر) في اللغة اسم فاعل من التأخير، وهو نقيض التقديم،...
Increase in the heat of menstrual blood.
"Ihtidām" (increase in heat): Muslim jurists underlined that the menstrual blood has its set of distinct characteristics, some of which are that it is warm and is accompanied by a burning sensation when it touches the skin. It is also said that the color of menstrual blood is dark red and sometimes blackish, contrary to non-menstrual blood, which is thin and light brownish or yellowish.
"Ihtidām": increase in heat and the flaring of fire. "Muhtadim": anything that has heat, including blood.