Where does “self-unloader” come from?

self-unloader (English) comes from English unloader, from English unload, from English Un-, from English still, from Old English stillan, from Proto-West Germanic stillijan, from Proto-West Germanic -jan, from Proto-Germanic -janą — he, she.

Ancestry of “self-unloader”, step by step

self-unloader traces back through two separate lines of ancestry.

via English unloader

StepLanguageWordMeaning
1EnglishunloaderAgent noun of unload; one who unloads
2EnglishunloadTo remove the load or cargo from; To remove from...
3EnglishUn-not
4EnglishstillNot moving; calm; Not effervescing; not...
5Old Englishstillanbecome calm, abate, subside; calm, pacify,...
6Proto-West Germanicstillijanto make still, quiet
7Proto-West Germanic-janCreates denominative verbs from nouns; Creates...
8Proto-Germanic-janąDerives denominatives from nouns and factitives...
9Proto-Indo-European-yétiCreates intransitive, often deponent,...
10Proto-Indo-Europeanyé-
11Chichewaiyehe, she

via English Self

StepLanguageWordMeaning
1EnglishSelfHimself, herself, itself, themself, themselves; that specific (person mentioned)
2Middle EnglishsalveAlternative form of sauf
3Old Englishsealfsalve
4Proto-West Germanicsalbusalve, ointment
5Proto-Germanicsalbōsalve, ointment
6Proto-Indo-Europeansolp-éh₂
7Proto-Indo-Europeanselp-fat, oil
Every word from Chichewa iye