Where does “fathead” come from?

fathead (English) comes from English fat, from French fat, from Old Occitan fat, from Latin fatuus, from Latin fātus, from Latin for, from Proto-Italic fāōr, from Proto-Indo-European bʰéh₂ti — to speak, to be talking.

fathead (English): An idiot; a fool; A cyprinid fish of the...

Definitions

  1. An idiot; a fool; A cyprinid fish of the...

Ancestry of “fathead”, step by step

fathead traces back through two separate lines of ancestry.

via English fat

StepLanguageWordMeaning
1EnglishfatCarrying more fat than usual on one's body;...
2Frenchfatconceited
3Old Occitanfat
4Latinfatuusfoolish, silly, simple; stupid; insipid,...
5Latinfātusspoken, said, told, foretold, related, predicted; having or had spoken, etc
6Latinfor"defective"; I speak, talk, say
7Proto-Italicfāōrspeak
8Proto-Indo-Europeanbʰéh₂tito speak, to be talking

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
Every word from Proto-Indo-European bʰéh₂ti