Or (shortened) ethan {ay-thawn'}; from an unused root (meaning to continue); permanence; hence (concrete) permanent; specifically a chieftain -- hard, mighty, rough, strength, strong.
H386. ethan
I. אֵתָן אֵיתָן, adjective perennial, ever-flowing, figurative permanent, as substantive steady flow, permanence; — absolute אֵיתָן Genesis 49:24 8t.; אֵתָן Job 33:19; suffix אֵיתָנוֺ Exodus 14:27; plural אֵיתָנִים Job 12:19; אֵתָנִים 1 Kings 8:2; Micah 6:2; (in form, an 'elative,' Ew§ 162 b = Arabic comparative and superlative); —
1 ever-flowing (opposed to אַכְזָב), אֵיתָן נַחַל Amos 5:24 an ever-flowing wady, Deuteronomy 21:4 (see Dr); as substantive in אֵיתָּן נַהֲרוֺת Psalm 74:15 rivers of steady flow; as substantive also Exodus 14:27 (J), the sea returned לְאֵיתָנוֺ to its steady flow, הָאֵיתָנִים יֶרַת 1 Kings 8:2 month of steady flowings = 7th mo., Oct.-;Nov. (post-Biblical Tisri).
2 figurative permanent, enduring הוּא אֵיתָן גּוֺי Jeremiah 5:15, i.e. a nation whose numbers never dwindle or fail, imperishable, א עֲצָמָיו ׳וְרִיב Job 33:19 Kt the strife of his bones is constant, Genesis 49:24 his bow abode ׳בְּא as an enduring, firm, one, ׳א מוֺשָֽׁבְךָ Numbers 24:21 ("" בַּסֶּלַע שִׂים), אֵיתָן נְוֵה Jeremiah 49:19 = 50:44 an abode of permanency (of Edom, and Babylon, suddenly depopulated by foe, figured as lion); ארץ מוסדי האיתנים Micah 6:2 ye ever-enduring ones, the foundations of the earth (but read probably with We הַאֲזִינוּ), Job 12:19 יְסַלֵּף אֵיתָנִים he subverteth them that are firmly seated (i.e. men established in hereditary offices or dignities). Very uncertain is Proverbs 13:15 אֵיתָן בִּגְדִים דֶּרֶךְ, perhaps firm, hard, rugged (Ew De Hi Now according to Str. the text is corrupt).