فرت1 فَرُتَ, aor. ـُ inf. n. فُرُوتَةٌ [said in the M to be a subst.], It (water, T, Msb) was, or became, sweet [or very sweet or most sweet (see فُرَاتٌ)]. (T, O, Msb, K.) A2:  فَرَتَ, (M, K,) aor. ـِ (M,) or ـُ (K,) inf. n فَرْتٌ, (M,) He acted vitiously, or unrighteously; or committed adultery, or fornication; syn. فَجَرَ. (M, K.) A3:  فَرِتَ, [aor. ـَ He became weak in his intellect, after having possessed ample intelligence. (IAar, T, O, K.) فِرْتٌ i. q. فِتْرٌ [The space measured by the extension of the thumb and fore finger]; (IJ, M, K;) a dial. var. of the latter word; as though formed by transposition. (M.) فُرَاتٌ, applied to water, (T, S, M, &c.,) and فُرَاهٌ, both chaste forms, and well known, like تَابُوتٌ and تَابُوهٌ, (Towsheeh, MF, TA,) Sweet: (S, O:) or very sweet: (K:) or of the sweetest kind: (T, M, L:) or that subdues thirst by its excessive sweetness: (Bd in xxv. 55:) so called, accord. to Z, because it breaks the vehemence of thirst, and allays it; as though from رَفَتَ, and formed by transposition: (TA:) you say مَآءٌ فُرَاتٌ, (S, M, O, K,) and in a copy of the K فِرَاتٌ also, (TA,) and مِيَاهٌ فُرَاتٌ, (S, M, O, K,) and فِرْتَانٌ, (M, Msb, in copies of the K فُرْتَانٌ, and in the CK فَرْتَانٌ,) like غِرْبَانٌ [pl. of غُرَابٌ], when فُرَاتٌ is pluralized, but this is rarely the case. (Msb.) b2:  الفُرَاتُ signifies also [The Euphrates;] the river of ElKoofeh; (S, Mgh, O, * K; *) a great, celebrated river, which issues from the limits of Er-Room, then passes by the borders of Syria &c., and, after meeting with the Tigris, forms therewith one river, and pours forth into the Sea [or Gulf] of Persia. (Msb, TA.) And الفُرَاتَانِ is an appellation applied to [The Euphrates and Tigris; i. e.] الفُرَاتُ and دِجْلَةُ: or, accord. to the S [and O] الفُرَاتُ and دُجَيْلٌ [The Euphrates and Dujeyl, which latter is a branch of the Tigris]. (TA.) b3:  Also The sea: (M, K:) so in a verse of Aboo-Dhu-eyb  describing pearls as found therein. (M.) فَرْتَنَا, (M, K,) accord. to Ibn-Habeeb from فَرَتَ [q. v.], but accord. to Sb the ن is radical, (M,) or الغَرْتَنَا accord. to IB, (TA in art. فرتن,) The fornicatress, or adultress. (M and K in this art. * and in art. فرتن.) And The female slave: (Th, and S and K in art. فرتن:) or so الفَرْتَنَا: and اِبْنُ الفَرْتَنَاThe son of the female slave that is a fornicatress. (IAar, TA in that art.) And اِبْنُ فَرْتَنَا The low, ignoble, mean, or sordid. (El-Ah wal, IB, TA.) b2:  Also, فَرْتَنَا, the name of A certain woman. (M and K in art. فرتن.) b3:  And الفَرْتَنَا The young one of the hyena. (K in art. فرتن.)