ثيلثَيْلٌ: see what next follows.ثِيلٌ The sheath of the penis of a camel (Lth, * Az, T, S, M, K) &c.; (K;) [i. e.,] of a he-goat  also, and of a bull: (M:) or the penis itself: (Lth, T, M, K:) sometimes also used in relation to a man: (M:) and ↓ ثَيْلٌ signifies the same; (K;) mentioned by Ibn-'Abbád; and IAth adds ثُولٌ. (TA.) Hence the prov., أَخْلَفُ مِنْ ثِيلِ الجَمَلِ [More contrary to what is usual than the sheath of the penis, or than the penis, of the camel]: for the camel, like the lion, is a retromingent. (TA.) A2:  A kind of plant; (S, K;) as also ↓ ثَيِّلٌ: (K:) a certain plant having a root and stem; when short, called نَجْمٌ: and a certain herb, or, as some say, a plant, that is found on the banks, or sides, of rivers, in meadows: and, some say, a species of the [plants, or trees, called] جَنْبَة, which grows in the territory of [the tribe of] Temeem, and becomes large, so that the sheep, or goats, lie in its shelter: (M:) AHn says, (M,) in the “ Book of Plants,” (Mgh,) the ثِيل, (M,) or ↓ ثَيِّل, (Mgh,) [both appellations now applied to triticum repens, or dog's grass,] is the نَجْمَة; called in Persian ريزوپادله [?]; (Mgh;) its leaves are like those of wheat, but shorter, and it spreads upon the face of the ground, extending far, and becoming com-plicated, or tangled, so as to be like felt (M, Mgh) upon the ground; (M;) it has many joints, or knots, and short internodal portions; and scarcely, or never, grows anywhere but over water, or in a place beneath which is water; (M, Mgh;) and it is one of the plants that are regarded as indicative of the existence of water: n. un. with ة: (M:) Lth says that the ثِيل is a certain plant that tangles upon the ground: Th, on the authority of IAar, says that it is a kind of plant said to be that called لِحْيَةُ التَّيْسِ: and Sh says that the ثِيلَة is a green small tree [or plant] resembling the first shoots that come forth from grain. (T.) ثَيِّلٌ: see ثِيلٌ, in two places.أَثْيَلُ A camel large in the ثِيل; (T, S, M, K;) wide therein: (M:) pl. ثِيلٌ. (K.) مَثِيلَة A place in which is the kind of plant called ثِيل. (Mgh.)