دَاحِضٌ
1.
[Slipping] has for a plural دُحْضٌ: occur- ring in a tradition, in the phrase دُحْضُ الأَقْدَامِ, meaning (assumed tropical:) those having no firmness, or stability, nor determination, or resolution, in affairs. (TA.)
2.
حُجَّتُهُمْ دَاحِضَةٌ, in the Qur'an, 42:15, means (tropical:) Their argument, or plea, or allegation, is null, or void: or, as IDrd says, on the authority of AO; it means مَدْحُوضَةٌ [rebutted]. (TA.)