Where does “fastcore” come from?

fastcore (English) comes from English Core, from English -core, from English hardcore, from English hard, from Old French hardi, from Old French hardir, from Frankish hardijan, from Proto-Germanic hardijaną — to travel, tour.

Ancestry of “fastcore”, step by step

fastcore traces back through two separate lines of ancestry.

via English Core

StepLanguageWordMeaning
1EnglishCoreThe birth name of Persephone/Proserpina, the queen of the Underworld/Hades, and goddess of the seasons and of vegetation. She is the daughter of Zeus and Demeter, and the wife of Hades
2English-coreApplied to various genres of music and...
3EnglishhardcoreHaving an extreme dedication to a certain...
4EnglishhardHaving a severe property; presenting difficulty;...
5Old Frenchhardihardy; tough; durable
6Old Frenchhardirto harden
7Frankishhardijanto harden, to make hard
8Proto-Germanichardijanąto make hard, strong; to harden
9Proto-Germanicharduzhard; brave
10Proto-Indo-Europeankert-times; to weave, twist together; time
11Proto-Turkic*keŕ-to travel, tour

via English fast

StepLanguageWordMeaning
1EnglishfastFirmly or securely fixed in place; stable; Firm...
2Middle Englishfastfast quickly
3Old Englishfæstefirmly, fastly, tightly
4Old English-eforming adverbs from adjectives; -ly
5Old English-enmæġþ + API → mæġden; cocc + API → cycen, cicen;...
6Old Norse-innUsed to create adjectives from nouns, meaning...
7Proto-Norse-īna-
8Proto-Germanic-īnaz-en
9Proto-Indo-European-iHnosCreates adjectives of materials
10Proto-Indo-European-no-adjectival suffix
Every word from Proto-Turkic *keŕ-