Where does “blackjack” come from?

I need to work through this chain carefully, but I notice there's a problem: the chain provided doesn't form a coherent etymology for "blackjack." The chain shows: - English black | Portuguese jaca | Malayalam ചക്ക | Old Norse bleikr | Proto-Indo-European bhleg- | Proto-Indo-European bhleg- | Proto-Indo-European bʰleyǵ- This appears to conflate two separate etymologies: 1. "black" (from PIE bʰleyǵ- through Old Norse bleikr) 2. "jack" (possibly from Portuguese jaca through Malayalam ചക്ക, which is jackfruit) However, the actual etymology of "blackjack" (the weapon, card game, or drink) doesn't follow this path. "Jack" in "blackjack" has different origins depending on the sense

blackjack (English): A common gambling card game in casinos, where the...

Definitions

  1. A common gambling card game in casinos, where the...

Ancestry of “blackjack”, step by step

blackjack traces back through two separate lines of ancestry.

via English black

StepLanguageWordMeaning
1EnglishblackAbsorbing all light and reflecting none; dark and...
2Middle EnglishblakeAlternative form of blak
3Old Englishblācshining, white, pale; bleak, pale, pallid, wan,...
4Old English-ianForms verbs from nouns and adjectives
5Old English-ōjan
6Proto-West Germanic-ōnCreates denominative verbs from nouns; Creates...
7Proto-Germanic-ōnąCreates denominative verbs from nouns; Creates...
8Proto-Indo-European-eh₂yétiCreates iterative/ frequentative/ intensive...
9Proto-Indo-European-yétiCreates intransitive, often deponent,...
10Proto-Indo-Europeanyé-
11Chichewaiyehe, she

via English jack

StepLanguageWordMeaning
1EnglishjackA coarse mediaeval coat of defence, especially...
2Anglo-Normanjacke
3Middle Frenchjaque
4Middle Frenchjacques
5Frenchjacquesplural of jacque; a stupid person; a jemmy or...
6LatinIacobusJacob; James; Saint James
7Ancient GreekἸάκωβος
8Ancient GreekἸακώβJacob
9HebrewיַעֲקֹבJacob
10Hebrewעָקֵבheel of the foot; heel
Every word from Chichewa iyeEvery word from Proto-Indo-European -yétiEvery word from Proto-Germanic -ōną