Where does “thickheadedly” come from?

thickheadedly (English) comes from English thickheaded, from English headed, from English head, from English -y, from Middle English -y, from Old English -iġ, from Proto-West Germanic -g, from Proto-Germanic -gaz — -y, -ic.

thickheadedly (English): In a thickheaded manner

Definitions

  1. In a thickheaded manner

Ancestry of “thickheadedly”, step by step

thickheadedly traces back through two separate lines of ancestry.

via English thickheaded

StepLanguageWordMeaning
1Englishthickheadedstupid, obtuse or dumb
2EnglishheadedOf a sheet of paper: having the sender's name,...
3EnglishheadThe part of the body of an animal or human which...
4English-yAdded to nouns and adjectives to form adjectives...
5Middle English-yDesignates an adjective, in many cases formed by...
6Old English-iġ-y, -ic
7Proto-West Germanic-gForms adjectives from nouns and verbs with a...
8Proto-Germanic-gaz-y
9Proto-Indo-European-ḱos-y, -ic

via English ly

StepLanguageWordMeaning
1EnglishlyAbbreviation of light-year
2VietnameselyAlternative spelling of li
Every word from Proto-Indo-European -ḱos