Where does “bitter” come from?

I appreciate the detailed instructions, but I notice there's a significant problem with the chain provided: it traces the suffix "-ing" and "-ary" morphemes, not the word "bitter." The chain doesn't actually support an etymology for "bitter" as a headword. Could you verify the chain? A proper etymology for "bitter" should trace through words like Old English "biter," Proto-Germanic "bitraz," and ultimately Proto-Indo-European roots—not through the morphological elements listed. Once you provide the correct chain, I'll write the one-sentence summary following all your rules.

bitter (English): Having an acrid taste; Harsh, piercing or...

Definitions

  1. Having an acrid taste; Harsh, piercing or...

Ancestry of “bitter”, step by step

bitter traces back through two separate lines of ancestry.

via English bit

StepLanguageWordMeaning
1EnglishbitA piece of metal placed in a horse's mouth and...
2Middle EnglishbitteA flexible container for water or wine; a waterskin or wineskin
3Old Englishbytbottle, flagon
4Proto-Germanic*buttjā
5Latinbuttiacask, barrel
6Ancient Greekβούττιον
7Ancient Greek-ῐονdiminutive suffix; "suffix forming...
8Proto-Indo-European-yósCreates adjectives from noun or verb stems

via Middle English bittre

StepLanguageWordMeaning
1Middle Englishbittrebitter
2Old Englishbiterbitter; bitter, severe, painful, biting
3Old Norsebitrbitter
4Proto-Germanicbitrazbitter
5Proto-Indo-Europeanbʰidrósbiting, splitting

Words derived from “bitter

Every word from Proto-Indo-European -yós