Where does “sourbread” come from?

sourbread (English) comes from English sour, from Middle English sour, from Old French essorer, from Vulgar Latin exaurare, from Latin ex, from Latin commūnicō, from Latin commūnis, from Old Latin com(m)oinis — resin.

Ancestry of “sourbread”, step by step

sourbread traces back through two separate lines of ancestry.

via English sour

StepLanguageWordMeaning
1EnglishsourHaving an acidic, sharp or tangy taste; Made...
2Middle Englishsoursour, acidic, bitter; foul-smelling, rancid;...
3Old Frenchessorerto fly up, soar
4Vulgar Latinexaurareto rise into the air; to expose to air; to rise...
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 bread

StepLanguageWordMeaning
1EnglishbreadA foodstuff made by baking dough made from...
2Middle Englishbredbread, pastry; food, nourishment
3Old Englishbredsurface; plank, board; table, tablet
4Old English-enmæġþ + API → mæġden; cocc + API → cycen, cicen;...
5Old Norse-innUsed to create adjectives from nouns, meaning...
6Proto-Norse-īna-
7Proto-Germanic-īnaz-en
8Proto-Indo-European-iHnosCreates adjectives of materials
9Proto-Indo-European-no-adjectival suffix
Every word from Proto-Germanic kweduz