A primitive root; to close (the lips or ears); by analology to contract (a window by bevelled jambs) -- narrow, shut, stop.
Englishman's Concordance
1) to shut, shut up, close 1a) (Qal) to shut, stop (of lips) 1b) (Hiphil) of the wicked stopping their ears (figuratively) Part of Speech: verb A Related Word by BDB/Strong’s Number: a primitive root Same Word by TWOT Number: 73
Brown-Driver-Briggs
[אטם] verbshut, shut up (Mishna אטם, compare אוֺטֶםstoppage, Aramaic אֲטַם; Arabic contract, stop, fortress; Assyrian a‰amu, in list of headgear, etc.=turban? DlW, No. 155) —
1 Kings 6:4 HEB:חַלּוֹנֵ֖י שְׁקֻפִ֥ים אֲטֻמִֽים׃ KJV: he made windows of narrow lights. INT: windows with frames of narrow
Psalm 58:4 HEB:פֶ֥תֶן חֵ֝רֵ֗שׁ יַאְטֵ֥ם אָזְנֽוֹ׃ NAS: a deaf cobra that stops up its ear, KJV: adder [that] stoppeth her ear; INT: cobra A deaf stops ear
Proverbs 17:28 HEB:חָכָ֣ם יֵחָשֵׁ֑ב אֹטֵ֖ם שְׂפָתָ֣יו נָבֽוֹן׃ NAS: wise; When he closes his lips, KJV: wise: [and] he that shutteth his lips INT: wise is considered closes his lips is prudent
Proverbs 21:13 HEB: אֹטֵ֣ם אָ֭זְנוֹ מִזַּעֲקַת־ NAS:He who shuts his ear to the cry KJV:Whoso stoppeth his ears at the cry INT:shuts his ear to the cry
Isaiah 33:15 HEB:מִתְּמֹ֣ךְ בַּשֹּׁ֔חַד אֹטֵ֤ם אָזְנוֹ֙ מִשְּׁמֹ֣עַ NAS: bribe; He who stops his ears KJV: of bribes, that stoppeth his ears INT: hold bribe stops his ears hearing
Ezekiel 40:16 HEB: וְחַלֹּנ֣וֹת אֲטֻמ֣וֹת אֶֽל־ הַתָּאִ֡ים NAS:[There were] shuttered windows KJV:And [there were] narrow windows INT: windows shuttered toward the guardrooms
Ezekiel 41:16 HEB:הַסִּפִּ֡ים וְהַחַלּוֹנִ֣ים הָ֠אֲטֻמוֹת וְהָאַתִּיקִ֤ים ׀ סָבִיב֙ NAS: The thresholds, the latticed windows KJV: The door posts, and the narrow windows, INT: the thresholds windows the latticed and the galleries round
Ezekiel 41:26 HEB: וְחַלּוֹנִ֨ים אֲטֻמ֤וֹת וְתִֽמֹרִים֙ מִפּ֣וֹ NAS:[There were] latticed windows KJV:And [there were] narrow windows INT: windows latticed and palm side
contract, stop, 
fortress; Assyrian a‰amu, in list of headgear, etc.=turban? DlW, No. 155) —