Where does “piratism” come from?

piratism (English) comes from English pirate, from English piratically, from English -ly, from English grisly, from Middle English grisely, from Old English grisliċ, from Old English -līċ, from Proto-Germanic *-līk.

Ancestry of “piratism”, step by step

piratism traces back through two separate lines of ancestry.

via English pirate

StepLanguageWordMeaning
1EnglishpirateA criminal who plunders at sea; commonly...
2EnglishpiraticallyIn a piratical manner
3English-lyUsed to form adjectives from nouns, the...
4EnglishgrislyHorrifyingly repellent; gruesome, terrifying;...
5Middle Englishgrisely
6Old Englishgrisliċgrisly, horrible; dreadful, horrid
7Old English-līċsuffix forming {{glossary|adjective}}s meaning...
8Proto-Germanic*-līk

via English ism

StepLanguageWordMeaning
1EnglishismAn ideology, system of thought, or practice that...
2English-ismUsed to form nouns of action or process or result...
3Latin-ismus-ism
4Ancient Greek-ισμόςForms abstract nouns
5Ancient Greek-μόςForms abstract nouns
6Proto-Indo-European-mósCreates action/result nouns from verb stems
Every word from Proto-Germanic *-līkEvery word from English -lyEvery word from Old English -līċ