ددندَدَنٌ (T, S, K) and دَدًا and دَدٌ; (T, K;) all  mentioned by El-Ahmar; (T;) and compared by Aboo-' Alee, in respect of having the last radical letter sometimes ن and sometimes an infirm letter and sometimes elided, to لَدُنْ and لَدَا and لَدْ; the second like قَفًا and عَصًا, and the third like يَدٌ, (T, TA,) and by some written دَدٌّ, with teshdeed; (TA; [but it is there implied that this is of doubtful authority;]) and the second and third said by some to be formed from the first, by the change of ن into ا and by the elision of ن; (TA;) Diversion, sport, play, or such as is vain, or frivolous; (T, S, K;) as also دَيْدٌ, [which should be mentioned in art. ديد,] and ↓ دَيَدَانٌ, (IAar, T, K, [not دَيْدَانٌ as in Freytag's  Lex., being followed in the K by the epithet مَحَرَّكَةٌ,]) and ↓ ديدون, (TA, [app. دَيْدُونٌ, of the measure فَيْعُولٌ, like تَيْقُورٌ,]) and ↓ دَيْدَبُونٌ, (IAar, T, S,) [mentioned also in the S in art. دبن,] by Sgh and in the K mentioned in art. ددب, and said in the K to be wrongly included by J in the present art. (TA.) دَدَنٌ and دَدَانٌ are  the only words in which the first and second radical letters are the same, without an intervening letter, and both movent. (S.) دَدَانٌ, applied to a sword, Blunt; (T, S, K;) that will not penetrate into the thing struck with it: (S:) and also sharp: thus bearing two contr. significations: (K:) or, accord. to Th, a sword with which trees are cut; called by others مِعْضَدٌ; and this is not necessarily the contr. of a blunt sword. (TA.) b2:  Also, applied to a man, [perhaps from the first of the significations mentioned above,] meaning لَاغَنَآءَ عِنْدَهُ [Not having, or not possessing, what suffices; or not profitable to any one]. (Fr, S, K.) دَيْدَنٌ (S, K) and ↓ دِيدَنٌ (TA on the authority of El-Khuwárezmee and El-Wáhidee) and ↓ دَيْدَانٌ (IJ, S, K) and ↓ ديدون [app. دَيْدُونٌ] (TA) and ↓ دَيْدَدَانٌ (K) A custom, manner, habit, or wont. (S, K, TA.) دِيدَنٌ: see what next precedes.دَيْدَانٌ: see what next precedes.دَيَدَانٌ: see دَدَنٌ.ديدون [app. دَيْدُونٌ]: see دَدَنٌ: b2:  and دَيْدَنٌ.دَيْدَبُونٌ: see دَدَنٌ.دَيْدَدَانٌ: see دَيْدَنٌ.