Where does “egghead” come from?

egghead (English) comes from English head, from English -y, from Middle English -y, from Old English -iġ, from Proto-West Germanic -g, from Proto-Germanic -gaz, from Proto-Indo-European -ḱos — -y, -ic.

egghead (English): A bald person, especially a man; A bald head; A...

Definitions

  1. A bald person, especially a man; A bald head; A...

Ancestry of “egghead”, step by step

egghead traces back through two separate lines of ancestry.

via English head

StepLanguageWordMeaning
1EnglishheadThe part of the body of an animal or human which...
2English-yAdded to nouns and adjectives to form adjectives...
3Middle English-yDesignates an adjective, in many cases formed by...
4Old English-iġ-y, -ic
5Proto-West Germanic-gForms adjectives from nouns and verbs with a...
6Proto-Germanic-gaz-y
7Proto-Indo-European-ḱos-y, -ic

via English egg

StepLanguageWordMeaning
1EnglisheggAn approximately spherical or ellipsoidal body...
2Middle EnglisheggenTo egg on; to encourage or provide motivation; To...
3Old Saxoneggianto harrow
4Old Norseeggjato incite, egg on to do
5Old Norseeggegg; edge
6Proto-Germanicagjōedge, corner
7Proto-Indo-Europeanh₂eḱ-sharp

Words derived from “egghead

Every word from Proto-Indo-European -ḱos