دحض1 دَحَضَتْ رِجْلُهُ, (S, A, K,) aor. ـَ (S,) inf. n. دَحْضٌ (S, A) and دُحُوضٌ, (A, TA,) His foot slipped. (S, A, K.) And دَحَضَ said of a man, He slipped. (Msb.) b2:  دَحَضَتِ الشَّمْسُ, (S, A, K,) aor. and inf. ns. as above, (TA,) (tropical:)  The sun declined (S, A, K) towards the place of setting, (TA,) عَنْ كَبِدِ السَّمَآءُ (S) or عن بَطْنِ السمآء (A) [from the meridian]; as though it slipped. (TA.) b3:  دَحَضَتْ حُجَّتُهُ, (S, A, Msb, K,) aor. ـَ (Msb,) inf. n. دُحُوضٌ, (S, K,) or دَحْضٌ, (Msb,) (tropical:)  His  argument, plea, allegation, or evidence, was, or became, null, or void. (S, A, * Msb, K.) A2: See also 4, in two places.4 ادحض, (A, TA,) inf. n. إِدْحَاضٌ, (S,) He made (S, A, TA) a man's foot, (A, TA,) and a man, (TA,) to slip; (S, A, TA;) as also ↓ دَحَضَ. (TA.) b2:  It (rain) made a place slippery. (TA.) b3:  (tropical:)  He (God, S, Msb, or a man, K) annulled, or rendered null or void, an argument, a plea, an allegation, or an evidence: (S, Msb, K:) he rebutted it; as also ↓ دَحَضَ, inf. n. دَحْضٌ. (TA; but in this instance, only the inf. n. of the latter verb is mentioned.) Thus in the Kur [xviii. 54, and xl. 5], لِيُدْحِضُوا بِهِ الحَقَّ (tropical:)  That they may, or might, rebut thereby the truth. (TA.) دَحْضٌ A slippery place; as also ↓ دَحَضٌ (S, K) and ↓ دَحُوضٌ (O, K) and ↓ مِدْحَضٌ (Freytag, from the Deewán of the Hudhalees,) [or مَدْحَضٌ?]: pl. دِحَاضٌ, (K,) [a pl. of the second,] like as جِبَالٌ is pl. of جَبَلٌ. (TA.) b2:  Also Water that causes slipping: pl. أَدْحَاضٌ. (TA.) دَحَضٌ: see the next preceding paragraph.دَحُوضٌ: see the next preceding paragraph.دَاحِضٌ [Slipping] has for a pl. دُحْضٌ: occur-ring in a trad., in the phrase دُحْضُ الأَقْدَامِ, meaning (assumed tropical:)  those having no firmness, or stability, nor determination, or resolution, in affairs. (TA.) b2:  حُجَّتُهُمْ دَاحِضَةٌ, in the Kur [xlii. 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.) مِدْحَضٌ [or مَدْحَضٌ?]: see دَحْضٌ.مَدْحَضَةٌ A cause of slipping; syn. مَزَلَّةٌ. (K.) You say, هٰذِهِ مَدْحَضَةٌ لِلْقَدَمِ [This is a cause of slipping to the foot]. (A.) And مَكَانٌ مَدْحَضَةٌ, in a trad. respecting the Sirát, means A place on which the feet will not remain firm. (TA.) مِدْحَاضٌ A place in which one slips much, or often: pl. مَدَاحِضُ. (TA.)