Semitic word root √mlk
The best known meaning of the Semitic root √mlk is “king”. The original basic meaning seems to be “council”, or more generally, information and requests traveling from one place to another. Kings have thus likely always been mere counsellors & advisors to higher powers.
Advice
Hebrew mlk = counsel, advice
מלך mlk malak : to consult, counsel, advise — Old Hebrew (Strong)
Akkadian mlk = counsel, advice
𒃌 milku : (government) advice, counsel; intelligence, resolution; council (bīt milki = council hall); plan, decision — Akkadian (AAF)
𒃌 malāku : (government) to discuss; to advise so. on sth.; to look after, mind; to discuss, confer; to consider, ponder; to advise, exhort; to be advised; to consider; to discuss — Akkadian (AAF)
𒇽𒃌 ; 𒇽𒀜𒄄𒄄 māliku : counsellor, adviser / advisor, councilman (?) — Akkadian (AAF)
miliktum : (a piece of) advice — Akkadian (AAF)
mitluktu : advice, deliberation — Akkadian (AAF)
Sumerian galga = planning, advice
The Sumerian character used in Akkadian is GALGA, which was apparently already sometimes read and spelled malga in Sumerian, as an Akkadian loanword.
𒃌 ; 𒈠𒀠𒂵 ĝalga; ma-al-ga : (fore)thought, plan(ning); understanding; instruction, advice — Sumerian (ePSD)
Messenger
Another meaning of similar words is “messenger” and “road”. In Hebrew, the spelling is mlˀk (with ˀAleph), and occurs without the M-prefix as lˀk It’s unclear if these meanings could be related to the √mlk root for “advice” (advice sent as a message), or to an M-prefixed √hlk root for “going” (messenger going out), or both. The derivation may be too old to be sure.
Hebrew mlˀk = messenger, ambassador
In Hebrew, the meaning of mlˀk as “messenger” is most famously found with the Biblical messengers of God, usually translated as angels. A related meaning is that of a “work”. Of the many terms for work, this one emphasizes that the work is commissioned.
מלאך mlˀk malak : ambassador, angel, envoy, messenger — Old Hebrew (Strong)
מלאכות mlˀkwt malakuth : commission, message — Old Hebrew (Strong)
מלאכה mlˀkh melakah : (commissioned) occupation, work — Old Hebrew (Strong)
לאך lˀk : to send; Base of מַלְאָךְ (= messenger; angel) and מְלָאכָה (= work). — Hebrew (Klein)
Akkadian malak, maluk = messenger, route, way
King
This is the most well-known meaning, though it is unclear what such a “king” really was. A common translation is that of an appointed local “governor”, e.g. of a city. If this meaning is derived from “counselor” or “messenger”, that local governor would have been something like a counselor to a higher ruler. The Klein dictionary mentions this derivation from “counselor”, but lists another possible one from “possession”, only found in Arabic & Ethiopian.
Hebrew mlk = king
Akkadian mlk = king of inferior rank
In Akkadian, the term is less often used or translated as “king”, and sometimes explained as a ruler of inferior rank. Apparently, the word was not used as a title itself. This points again to the term being derived from “counselor”, and regional governors being seen as “counselors” or “messengers” to higher rulers. The Norris dictionaries have some commentary on this.
𒂷𒆪 ; 𒂷𒆠 ; 𒂷𒋻 malku; malki; malkut : king; Heb. מֶלֶךְ; Malik represents a king of inferior rank; generally those subordinate to the sar. — Akkadian (Norris)
𒈠𒌨 ; 𒂷𒆪 malik; malku : monarch, king, ruler; Heb. מֶלֶך; Sar invariably follows the king’s name as the royal title. Malik often appears upon other occasions, with the same meaning apparently, but I usually put “monarch” or “ruler” when the two words occur in the same sentence. — Akkadian (Norris)
malku(m); maliku(m) : prince, king — Akkadian (Black)