From araph; the nape or back of the neck (as declining); hence, the back generally (whether literal or figurative) -- back ((stiff-)neck((-ed).
see HEBREW araph
H6203. oreph
עֹ֫רֶף noun masculineDeuteronomy 31:27 back of neck, neck; — ׳ע absolute Joshua 7:12 +; construct Genesis 49:8 +; suffix עָרְמִּי Job 16:12, עָרְמְּךָ Deuteronomy 31:27, etc.; —
1 back of neck of fleeing foe בְּע ׳יָָֽדְךָ ׳וגו Genesis 49:8 (poem in J), compare בְּעָרְמִּי וְאָחַז Job 16:12 (figurative); Exodus 23:27 (E), Psalm 18:41 = 2 Samuel 22:41; turn (מָּנָה הָפַח,) one's back before (לִפְנֵי) a foe Joshua 7:8, 12 (JE), absolute Jeremiah 48:39; figurative of apostasy ע ׳מָּנָה אֶל 2:27; 32:33 (opposed to פָנִים מָּנָה) absolute ע ׳וַיִּתְּנּוּ2 Chronicles 29:6; of ׳יs disfavour ׳ע אֶרְאֵם פָנִים וְלֹא Jeremiah 18:17 with the back and not the face will I look at them.
2 figurative in ׳קְשֵׁהעֿ stiff of neck, i.e. obstinate, of Israel Exodus 32:8; 33:3, 5; 34:9 (all J E), Deuteronomy 9:6, 13; הַקָּשֶׁה עָרְמְּךָ 31:27; with verb ע ׳הִקְשָׁה i.e. be obstinate, intractable 10:16; Jeremiah 7:26; 17:23; 19:15; 2 Kings 17:14 (twice in verse); Nehemiah 9:16-17, 29; 2 Chronicles 30:8; compare ע בַּרְזֶל ׳גִּיד Isaiah 48:4 ("" אָ֑תָּה קָשֶׁה); ע ׳הִקְשָׁה of individual 2 Chronicles 36:13; Proverbs 29:1.
3 of bird: nip its head עָרְמּוֺ מִמּוּל Leviticus 5:8 (P).