(ב) כֹּ֤ה אָמַר֙ ה׳ צְבָא֔וֹת פָּקַ֕דְתִּי אֵ֛ת אֲשֶׁר־עָשָׂ֥ה עֲמָלֵ֖ק לְיִשְׂרָאֵ֑ל אֲשֶׁר־שָׂ֥ם לוֹ֙ בַּדֶּ֔רֶךְ בַּעֲלֹת֖וֹ מִמִּצְרָֽיִם׃ (ג) עַתָּה֩ לֵ֨ךְ וְהִכִּיתָ֜ה אֶת־עֲמָלֵ֗ק וְהַֽחֲרַמְתֶּם֙אֶת־כׇּל־אֲשֶׁר־ל֔וֹ וְלֹ֥א תַחְמֹ֖ל עָלָ֑יו וְהֵמַתָּ֞ה מֵאִ֣ישׁ עַד־אִשָּׁ֗ה מֵֽעֹלֵל֙ וְעַד־יוֹנֵ֔ק מִשּׁ֣וֹר וְעַד־שֶׂ֔ה מִגָּמָ֖ל וְעַד־חֲמֽוֹר׃ {ס}
(2) “Thus said the LORD of Hosts: I am exacting the penalty for what Amalek did to Israel, for the assault he made upon them on the road, on their way up from Egypt. (3) Now go, attack Amalek, and proscribe all that belongs to him. Spare no one, but kill alike men and women, infants and sucklings, oxen and sheep, camels and asses!”
"Utterly destroy everything that is theirs."
Utterly destroy. This is what the verb וְהַֽחֲרַמְתֶּם֙ means.
Let's get down to grammar basics. This is from the verbal root - shoresh - √חרם - to utterly destroy.
It is in second person plural, and in the hifil (causative) binyan: "you shall cause them to be utterly destroyed".

In a Sefaria sheet last summer I explored the contranymics of possession / dispossession; the verb for "dispossess" can also mean "to become impoverished", suggesting that when we dispossess others, we somehow become [morally] impoverished ourselves).
Va'etchanan 5784 The Contranymics of Possession
https://www.sefaria.org/sheets/584150.17?lang=bi
(ז) וַיַּ֥ךְ שָׁא֖וּל אֶת־עֲמָלֵ֑ק מֵֽחֲוִילָה֙ בּוֹאֲךָ֣ שׁ֔וּר אֲשֶׁ֖ר עַל־פְּנֵ֥י מִצְרָֽיִם׃ (ח) וַיִּתְפֹּ֛שׂ אֶת־אֲגַ֥ג מֶלֶךְ־עֲמָלֵ֖ק חָ֑י וְאֶת־כׇּל־הָעָ֖ם הֶחֱרִ֥ים לְפִי־חָֽרֶב׃ (ט) וַיַּחְמֹל֩ שָׁא֨וּל וְהָעָ֜ם עַל־אֲגָ֗ג וְעַל־מֵיטַ֣ב הַצֹּאן֩ וְהַבָּקָ֨ר וְהַמִּשְׁנִ֤ים וְעַל־הַכָּרִים֙ וְעַל־כׇּל־הַטּ֔וֹב וְלֹ֥א אָב֖וּ הַחֲרִימָ֑ם וְכׇל־הַמְּלָאכָ֛ה נְמִבְזָ֥ה וְנָמֵ֖ס אֹתָ֥הּ הֶחֱרִֽימוּ׃ {פ}
(7) Saul destroyed Amalek from Havilah all the way to Shur, which is close to Egypt, (8) and he captured King Agag of Amalek alive. He proscribed [utterly destroyed] all the people, putting them to the sword; (9) but Saul and the troops spared Agag and the best of the sheep, the oxen, the second-born, the lambs, and all else that was of value. They would not proscribe them [ie they would not destroy livestock of value]; they proscribed [uttterly destroyed] only what was cheap and worthless.
https://jewishstudies.duke.edu/news/destroying-amalek
"Proscribed" (cherem) set aside and forbidden to use, whether due to consecration to the LORD (Lev 27:28) or because it is an abomination. (Jewish Study Bible, note p. 452)
(יח) וְרַק־אַתֶּם֙ שִׁמְר֣וּ מִן־הַחֵ֔רֶם פֶּֽן־תַּחֲרִ֖ימוּ וּלְקַחְתֶּ֣ם מִן־הַחֵ֑רֶם וְשַׂמְתֶּ֞ם אֶת־מַחֲנֵ֤ה יִשְׂרָאֵל֙ לְחֵ֔רֶם וַעֲכַרְתֶּ֖ם אוֹתֽוֹ׃
(18) But you must beware of that which is proscribed, or else you will be proscribed: if you take anything from that which is proscribed, you will cause the camp of Israel to be proscribed; you will bring calamity upon it.
