دهدردُهْدُرٌّ a noun signifying What is false, or vain; a lie; syn. بَاطِلٌ and كَذِبٌ: as also دُهْدُرَّيْنِ, (K,) its dual, (TA,) or دُهْ دُرَّيْنِ, or دُهْ دُرَّيْنْ: (as in different copies of the S:) whence دُهْدُرَّيْنِ and ↓ دُهْدُرِّيَّةٌ are epithets applied to a liar; or a great or habitual liar: and accord. to Az, the Arabs used to say, دُهْدُرَّانِ لَا يُغْنِياَنِ عَنْكَ شَيْئًا [Lies will not avail thee aught]: and دُهْدُنٌّ signifies the same as دُهْدُرٌّ. (TA.) b2:  دُهْدُرَّيْنِ is also a noun, (K,) i. e. a verbal noun, (TA,) signifying He was, or has become, unoccupied, or without work; syn. بَطَلَ; (K;) like سَرْعَانَ for سَرُعَ, and هَيْهَاتِ for بَعُدَ. (TA.) Hence the prov., (TA,) دُهْدُرَّيْنِ سَعْدُ القَيْنِ, (As, K,) without the conjunction وَ [after the first word], and دهدرّين being written as one word, (TA,) meaning Saad the blacksmith became, or has become, unoccupied, or without work; not being employed because of the people's being diverted from other things by drought (As, K) and distress. (TA.) Some say سَاعدُ القَيْنِ: and Aboo-'Obeydeh  Maamar Ibn-El-Muthennà relates it thus: دهدرّين سَعْدَ القَيْن, with سعد in the accus. case, and says that دهدرّين is governed in the accus. case by a verb understood; apparently meaning that it is a noun signifying البَاطِلُ, dual of دُهْدُرٌّ, not a verbal noun, as though the prov. meant Cast ye away what is false, or vain, and Saad the blacksmith: but what he says is not correct. (TA.) Or a certain blacksmith asserted his name to be Saad for some time, and then his lying became manifest; so this was said to him; meaning, Thou hast added falsehood to falsehood, O Saad the blacksmith. (K.) It is also related separately; (K;) and so J and others relate it; saying ده درّين: (TA:) [in one copy of the S, I find it written دُهْ دُرَّيْنْ: in another, دُهْ دُرَّيْنِ:] دُهْ being  an imperative from الدَّهَآءُ; its final radical letter being transposed to the place of the medial, so that it becomes دُوْهْ, and the و being then rejected because of the two quiescent letters, (K,) so that it becomes دُهْ, like as is done in the case of قُلْ: (TA:) and دُرَّيْنِ being from دَرَّ, “it was  consecutive; ” (K;) by the dual form being meant repetition, as in the case of لَبَّيْكَ &c.: (TA:) so that the meaning is Be thou very lying (K) and cunning, (TA,) O Saad (K) the blacksmith: (TA:) and this explanation, says IB, is good, except inasmuch as that the د in درّين thus derived should be with fet-h; or, he adds, it may be with damm to assimilate it to the د in دُهْ [like as القَيْنِ is terminated with kesr to assimilate it to دُرَّيْنِ]. (TA.) Or the origin of the saying was this: Saad the blacksmith was a Persian, who went about the districts of ElYemen, working for the people; and when he became without work in a district, he used to say, in Persian, دِهْ بَدْرُودْ: [so in a copy of the S; and this, or دِهْ بِدْرُودْ, is the correct reading: in another copy of the S, دَهْ بَدُورُدْ: and in the copies of the K, دِهْ بَدْرُودْ:] (S, K:*) meaning, [O town, or village,] farewell: to acquaint them that he was going forth on the morrow: (K:) or meaning I am going forth to-morrow: (S:) in order that he might be employed: and they arabicized the expression, and made him the subject of a prov. with respect to lying; and said, When ye hear of the blacksmith's departure at night, he is assuredly coming in the morning. (S, K.) Some say that the prov. is elliptical, for بَطَلَ قَوْلُ سَعْدٍ الخ [False is the saying of Saad &c.]. (TA.) [This is mentioned in the S in art. در.]دُهْدُرَّيَّةٌ: see above, first sentence.