Apparently from 'al; good for nothing, by anal. Vain or vanity; specifically an idol -- idol, no value, thing of nought.
see HEBREW 'al
H457. elil
אֱלִיל noun masculine (etymology uncertain: most probably akin to Syriac weak, feeble, poor; perhaps also in usage [compare b] felt to suggest אַל not; compare Che on Isaiah 2:8) insufficiency, worthlessness.
a. Zechariah 11:17 הָאֱלִיל רֹעִי the shepherd of worthlessness = the worthless shepherd, Job 13:4 אֱלִל רֹפְאֵי worthless physicians ("" טֹפְלֵישֶֿׁקֶר), Jeremiah 14:14 Qr concrete a thing nought (uttered by prophets), but here אֱלִיל קֶסֶם a worthless divin. ("" לִבָּם תַּרְמִית שֶׁקֶר, חֲזוֺן) should perhaps be read (compare Gf).
b. especially plural אֱלִילִים concrete worthless gods, idols (compare הֲבָלִים) (possibly originally an independent word = gods, compare Sabean אלאלת, & see NöSBAk 1882, p. 1191, but even if so, associated by the prophets with idea of worthlessness, & used by them in iron. contrast with אֱלֹהִים אֵלִים,) Leviticus 19:4 (not to be made) 26:1 (both H), Isaiah 2:8, 18, 20 (twice in verse) (of silver & gold), 10:10 הָאֱלִיל מַמְלְכוֺת (collective) kingdoms of idolatrous worthlessness, 10:11; 19:1, 3(of Egypt) 31:7 (twice in verse); Ezekiel 30:13 (Egypt), Habakkuk 2:18 ׳א אִלְּמִים dumb idols, Psalm 96:5 ( = 1 Chronicles 16:26) all the gods of the nations are ׳א vain, worthless gods 1Chron 97:7.
II. אלל (√ assumed for following words).