Or rowsh (Deut. 32:32) {roshe}; apparently the same as ro'sh; a poisonous plant, probably the poppy (from its conspicuous head); generally poison (even of serpents) -- gall, hemlock, poison, venom.
see HEBREW ro'sh
H7219. rosh
II. ראשׁ and ( Deuteronomy 32:32) רוֺשׁ noun masculine32:33 a bitter and poisonous herb, them venom, always figurative; —
1 a bitter and poisonous herb, + (or "") לַעֲנָה Deuteronomy 29:17; Lamentations 3:19, so (ראֹשׁ מֵי) Jeremiah 9:14; 23:15; ר ׳מֵי (without ׳ל) 8:14; עִנְּכֵירֿוֺשׁ Deuteronomy 22:32 ("" מְרֹרֹת); וּתְלָאָה ראֹשׁ Lamentations 3:5; ׳ר alone Psalm 69:22, כָּראֹשׁ מִשְׁמָּטוּמָּרַח Hosea 10:4, לר ׳הְפַכְתֶּם מִשְׁמָּט Amos 6:12.
2 venom, of serpents, ׳ר מְּתָנִים Deuteronomy 32:33; Job 20:16.
רוֺשׁ poison, Deuteronomy 32:32, see II.ראֹשׁ.