Where does “black square” come from?

black square (English) comes from English square, from Middle English square, from Old French esquarre, from Vulgar Latin exquadra, from Latin ex, from Latin commūnicō, from Latin commūnis, from Old Latin com(m)oinis — resin.

black square (English): A predominantly black image, posted by users of social media, as a demonstration of support for awareness and protest campaigns, particularly those related to racism and police brutality

Definitions

  1. A predominantly black image, posted by users of social media, as a demonstration of support for awareness and protest campaigns, particularly those related to racism and police brutality

Ancestry of “black square”, step by step

black square traces back through two separate lines of ancestry.

via English square

StepLanguageWordMeaning
1EnglishsquareA polygon with four sides of equal length and...
2Middle EnglishsquareA square tool used to ensure a right angle
3Old Frenchesquarresquare
4Vulgar Latinexquadra
5LatinexA name of the letter "X"; out of, from
6Latincommūnicōto impart, share
7Latincommūniscommon, commonplace, ordinary, general, universal, shared, shared alike, of both sides, belonging to two or more together
8Old Latincom(m)oinis
9Proto-Italickommoiniscommon
10Proto-Indo-Europeanḱom-moy-ni-held in common
11Proto-Indo-Europeanḱómbeside, near, by, with
12Proto-Indo-EuropeanḱeDeictic particle, here; Post-positional...
13Middle Englishkyt
14Germankittputty certain kinds of cement used for fixing e.g. window panes
15Old High Germankuti
16Proto-West Germanickwidugum, resin
17Proto-Germanickweduzresin

via English Black

StepLanguageWordMeaning
1EnglishBlackAlternative letter-case form of black
2Old Frenchblancwhite
3Late Latinblancuswhite
4Frankishblankbright; gleaming, white, blinding; bright,...
5Proto-Germanic*blank
6Proto-Germanicblankazbright, shining, white, gleaming, blinding
7Proto-Indo-Europeanbhleg-to shine, white; to shine, burn, scorch
Every word from Proto-Germanic kweduzEvery word from Proto-West Germanic kwiduEvery word from Old High German kuti
black square — Etymology, Origin & Word History | Etymology Explorer