Where does “крепколобый” come from?

крепколобый (Russian) comes from Russian кре́пкий, from Proto-Slavic krěpъkъ, from Proto-Slavic -ъkъ, from Proto-Slavic -kъ, from Proto-Indo-European -kos — Creates deadjectival and desubstantival...

крепколобый (Russian): thick-headed

Definitions

  1. thick-headed

Ancestry of “крепколобый”, step by step

крепколобый traces back through two separate lines of ancestry.

via Russian кре́пкий

StepLanguageWordMeaning
1Russianкре́пкийstrong, firm, solid
2Proto-Slavickrěpъkъstrong
3Proto-Slavic-ъkъForms diminutives from old u-stem nouns;...
4Proto-Slavic-kъDeverbal, forms token nouns; From expressive or...
5Proto-Indo-European-kosCreates deadjectival and desubstantival...

via Russian лоб

StepLanguageWordMeaning
1Russianлобforehead
2Proto-Slaviclъbъskull
3Proto-Indo-Europeanlubʰo—
Every word from Proto-Indo-European -kos →Every word from Proto-Slavic -kъ →Every word from Proto-Slavic -ъkъ →