Where does “fullwidth” come from?

fullwidth (English) comes from English full, from Middle English fúl, from Old English full, from Proto-West Germanic full, from Proto-Germanic fullaz, from Proto-Indo-European pl̥h₁nós, from Proto-Indo-European pleh₁- — to fill.

fullwidth (English): Of a text character, occupying the space of two alphanumeric characters in a monospace font, or two "normal" text columns

Definitions

  1. Of a text character, occupying the space of two alphanumeric characters in a monospace font, or two "normal" text columns

Ancestry of “fullwidth”, step by step

fullwidth traces back through two separate lines of ancestry.

via English full

StepLanguageWordMeaning
1EnglishfullContaining the maximum possible amount that can...
2Middle Englishfúlvery; much; to a great extent
3Old Englishfullfull, filled, complete, entire; a beaker; a cup,...
4Proto-West Germanicfullfull
5Proto-Germanicfullazfull; the whole, the entire
6Proto-Indo-Europeanpl̥h₁nósfull
7Proto-Indo-Europeanpleh₁-to fill

via English width

StepLanguageWordMeaning
1EnglishwidthThe state of being wide; The measurement of the...
2EnglishwideHaving a large physical extent from side to side;...
3Old Englishwīdwide, vast, broad, long; distant, far
4Proto-Germanicwīdazwide; broad
5Proto-Indo-Europeanh₁weydʰh₁osset apart, asunder, in two
6Proto-Indo-Europeandwi-two; apart, asunder
7Proto-Indo-Europeandwóh₁two
Every word from Proto-Indo-European pleh₁-Every word from Proto-Indo-European pl̥h₁nósEvery word from Proto-Germanic fullaz