رعن1 رَعُنَ, (S, K,) and رَعِنَ, and رَعَنَ, (K,) [aor. of the first رَعُنَ, and of the second and third رَعَنَ,] inf. n. [of the first] رُعُونَةٌ, and [of the second, or second and third,] رَعَنٌ, (S, * K,) He was, or became, foolish, stupid, unsound in intellect or understanding, or deficient therein, and lax, flaccid, slack, or languid: (S, K:) or رُعُونَةٌ and رَعَنٌ signify the being foolish, or stupid: and also the being soft, weak, relaxed, or languid. (KL.) b2:  And رَعَنٌ also signifies [simply] The being slack, or loose; or slackness, or looseness; as in the saying of a rájiz, (S, TA,) namely, Khitám El-Mujáshi'ee, (TA,) describing a she-camel, وَرَحَلُوهَا رِحْلَةً فِيهَا رَعَنْ [And they saddled her in a manner of saddling in which was a slackness, or looseness]; i. e. they  did not bind her saddle firmly, by reason of fear and haste. (S, TA.) Also The being unsteady, or in a state of commotion or agitation: and quickly changing or altering. (Meyd, in explanation of a prov. cited below, voce أَرْعَنُ.) [and accord. to Freytag, as on the authority of Meyd, Haste of pace.] b3:  And رُعُونَةٌ signifies also The being beautified, and adorned: and رَعَنٌ, the displaying oneself adorned. (KL.) A2:  رَعَنَتْهُ الشَّمْسُ, (S, K,) inf. n. رَعْنٌ, (KL,) The sun rendered him relaxed, (S, KL,) or weak, or languid: (KL:) or pained his brain, so that he became relaxed thereby, and swooned. (K.) And رُعِنَ He (a man) became thus affected by the sun. (TA.) Pass. part. n. ↓ مَرْعُونٌ, signifying Thus affected by the sun; (S, TA;) applied to a man. (TA.) 4 مَا أَرْعَنَهُ How foolish, stupid, unsound in intellect or understanding, or deficient therein, and lax, flaccid, slack, or languid, [or how foolish, or stupid, and how soft, weak, relaxed, or languid, (see 1,)] is he! (S, K.) رَعْنٌ A prominence, or projecting part, (S, K,) or such as is large, (TA,) of a mountain: (S, K:) pl. رُعُونٌ and رِعَانٌ. (S, K.) And A long mountain: (K:) or, accord. to Lth, a mountain that is not long: pl. رُعُونٌ. (TA.) رَعَنَّكَ a dial. var. of لَعَلَّكَ. (Lh, K.) رَعُونٌ Having much motion; or moving itself much. (K.) b2:  And Hard, or strong. (K.) A2: And (as some say, TA) The darkness of night: (K, TA:) or [simply] darkness. (TA.) رَاعِنَا in the phrase لَا تَقُولُوا رَاعِنَا, in the Kur [ii. 98, and occurring again in iv. 48], is said to be a word meant to convey a reviling of the Prophet, derived from [the inf. n.] الرُّعُونَةُ: El-Hasan  read رَاعِنًا, with tenween: and Th says that the phrase means Say not ye a lie, and mockery, and foolishness. (TA.) [See also 4 in art. رعى.]أَرْعَنُ, (S, K,) applied to a man, (S,) Foolish, stupid, unsound in intellect or understanding, or deficient therein, and lax, flaccid, slack, or languid: (S, K:) or, so applied, foolish, or stupid: (KL:) [and also soft, weak, relaxed, or languid: (see 1:)] and foolish, or stupid, and hasty, in speech: (K:) fem., applied to a woman, رَعْنَآءُ: (S:) [pl. رُعْنٌ.] b2:  [Its primary application, though I do not find it mentioned, is probably to a mountain, as meaning Having a رَعْن, or prominence, or projecting part: accord. to Freytag, “ is qui habet  ” and then poetically used, in the Deewán of Jereer, as signifying a mountain. b3:  And hence,] also, applied to a man, (assumed tropical:)  Having a long nose [likened to a رَعْن]. (TA.) b4: Also (assumed tropical:)  An army having redundant parts, or portions, (K, TA,) like the رِعَان of mountains: (TA:) or an army has this epithet applied to it as being likened to the رَعْن of a mountain: or, as some say, the epithet thus applied means in a state of commotion by reason of its numerousness. (S.) b5:  El-Basrah is termed الرَّعْنَآءُ, as being likened to the رَعْن of a mountain; (IDrd, S, K;) i. e., because of a bend in it: (TA:) or because of the abundant flow of the river there, and its sultry heat: (Az, MF:) or because of the ease and plenty that are in it, and as being likened to the woman to whom this epithet is applied; or because of the languidness and changeableness of its air. (Er-Rághib, TA.) b6:  And الرَّعْنَآءُ is also a name of A sort of grapes, of Et-Táïf, (K, TA,) white, and long in the berries. (TA.) A2:  أَرْعَنُ مِنْ هَوَآءِ البَصْرَةِ is a prov., meaning More unsteady and changeable than the air of El-Basrah. (Meyd.) مَرْعُونٌ: see 1, last sentence.