Where does “pretty penny” come from?

pretty penny (English) comes from English penny, 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.

pretty penny (English): Chiefly preceded by a: a considerable amount of money; a high income or price

Definitions

  1. Chiefly preceded by a: a considerable amount of money; a high income or price

Ancestry of “pretty penny”, step by step

pretty penny traces back through two separate lines of ancestry.

via English penny

StepLanguageWordMeaning
1EnglishpennyIn the United Kingdom and Ireland, a copper coin...
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 pretty

StepLanguageWordMeaning
1EnglishprettyPleasant to the sight or other senses;...
2Middle Englishprety
3Old Englishprættiġtricky, crafty, sly, cunning, wily, astute
4Proto-Germanicprattugazboastful, sly, slick, deceitful, tricky, cunning
5Proto-Germanicprattuzboastful talk; deceit, trickery, stratagem, list,...
6Proto-Indo-Europeanbrodnó-to wander about
Every word from Proto-Indo-European -ḱos