اثغم It (a valley) produced the kind of plant called ثَغَام: (Ḳ:) or abounded therewith. (A, TA.)

And ‡ It (the head) became like the ثَغَامَة in whiteness. (Ḳ, TA.)

ثَغَامٌ A kind of plant, (Ṣ, Mṣb, Ḳ, TA,) generally (Mṣb) found in the mountains, (Ṣ, Mṣb,) having a green stem, (TA,) which becomes white when it dries, (Ṣ, Mṣb, TA,) and to which hoariness is likened; (Ṣ, Mṣb; [Golius, app. misled by a false reading in a copy of the Ṣ, says “simile anetho;”]) it has a thick [head, or blossom, such as is called] سَنَمَة, and [it is said that] it does not grow save upon a black mountain-top, and is found in Nejd and Tihámeh: (TA:) AʼObeyd says that it is a kind of plant, (TA,) IF, that it is a tree, (Mṣb,) with a white blossom and fruit, (Mṣb, TA,) to which hoariness is likened: (TA:) it is called in Persian درمنه; (Ḳ; [written in different copies of that work دِرَمْنَه and دَرَّمْنَه and دَرَمْنَه; the last of which is said in the TA to be the right reading; a word said to mean wormwood, and hyssop; or, accord. to Meninski, as mentioned by Freytag, zedoary; but this last is called in Persian زُرُنْبَا, with which word درمنه may have been confounded;]) or درمنه اسبيد, (Ṣ,) or دَرْمَنَه إِسْپِيد, in which [SM thinks] the former word is a contraction of دَرْمِيَانَه; the two together meaning “in the middle white:” (TA:) the n. un. is with ة {ثَغَامَةٌ}: (Ṣ, Ḳ:) andأَثْغَمَآءُ↓ is a quasi-pl. n.; (Ḳ;) as though the اء were a substitute for the ة of أَثْغِمَةٌ. (TA.)

ثَاغِمٌ A colour white like the ثَغَام: (Ḳ:) in the L, a head wholly white. (TA.)