Where does “jellybrain” come from?

jellybrain (English) comes from English jelly, from English jealous, from Middle English jelous, from Old French jalous, from Latin zēlōsus, from Latin zēlus, from Ancient Greek Ζῆλος, from Proto-Indo-European yeh₂- — to go; to go in, enter; to ride, to travel.

jellybrain (English): A muddled thinker; a stupid person

Definitions

  1. A muddled thinker; a stupid person

Ancestry of “jellybrain”, step by step

jellybrain traces back through two separate lines of ancestry.

via English jelly

StepLanguageWordMeaning
1EnglishjellyA dessert made by boiling gelatine, sugar and...
2EnglishjealousSuspecting rivalry in love; troubled by worries...
3Middle EnglishjelousJealous about a relationship; fearful about one's...
4Old Frenchjalouseager; zealous; jealous
5Latinzēlōsusjealous
6Latinzēluszeal, emulation
7Ancient GreekΖῆλοςZelus
8Proto-Indo-Europeanyeh₂-to go; to go in, enter; to ride, to travel

via English brain

StepLanguageWordMeaning
1EnglishbrainThe control center of the central nervous system...
2Middle EnglishbraynThe brain or cerebrum; the organ of thought;...
3Old Englishbræġnbrain
4Proto-West Germanic*bragnbrain
5Proto-Germanicbragnąbrain
6Proto-Indo-Europeanmregʰnomskull, brain
7Proto-Indo-Europeanmen-to think, mind; spiritual activity; to stay,...
Every word from Proto-Indo-European yeh₂-