Lexical Definition

‎עָתַר‎ ʻâthar (aw-thar') be abundant H:V
a primitive root

deceitful, multiply.

1) to be abundant
1a) (Niphal) to be plentiful
1b) (Hiphil) to multiply, become abundant

Usage: 2 forms in 2 verses
Form Translated As     In Verse(s)
וְהַעְתַּרְתֶּ֥ם and you have multiplied Ezek.35.13
וְ֝נַעְתָּר֗וֹת and abundant Prov.27.6

Brown-Driver-Briggs

II. [‎עָתַר‎] verb be abundant, si vera lectio (as Aramaic loan-word; ‎עֲתַר‎, , be rich = Hebrew ‎עָשַׁר‎); —

Niph`al Participle feminine plural ‎נַעְתָּרוֺת‎ Prov 27:6 (of enemy's kisses; De excessive; opposed to ‎נֶאֱמָנִים‎); Toy proposes ‎נֶעֱקָשׁוֺת‎, or ‎נַעֲוֺת‎, crooked, hypocritical. Hiph`il Perfect 2 masculine plural ‎הַעְתַּרְתֶּם עָלַי דִּבְרֵיכֶם‎ Ezek 35:13 ye have multiplied against me your words (|| ‎וַתַּגְדִּילוּ‎ ‎עָלַי בְּפִיכֶם‎), strike out as gloss Co after ᵐ5, Toy reads singular, and thinks verb due to Aramaizing scribe.

Brown-Driver-Briggs References

Book Refs
Proverbs 27:6
Ezekiel 35:13