late 14c., mussillage, "viscous substance found in vegetable material," from Old French mucilage (14c.) and directly from Late Latin mucilago "musty or moldy juice" (4c.), from Latin mucere "be musty or moldy," from mucus "mucus" (see mucus). Meaning "adhesive gum" is attested by 1859.
early 15c., "viscous, sticky; slimy and ropy," from Medieval Latin muscilaginosus, from Late Latin mucilaginosus, from mucilago (see mucilage). Related: Mucilaginously; mucilaginousness.
"viscid fluid secreted by the mucous membranes of animals," 1660s (replacing Middle English mucilage), from Latin mucus "slime, mold, mucus of the nose, snot," from PIE root *meug- "slippery, slimy," with derivatives referring to wet or slimy substances or conditions (source also of Latin emungere "to sneeze out, blow one's nose," mucere "be moldy or musty," Greek myssesthai "to blow the nose," myxa "mucus;" Sanskrit muncati "he releases"). Old English had horh, which may be imitative.
"a savoury dish of Italian origin, consisting of a base of dough, spread with a selection of such ingredients as olives, tomatoes, cheese, anchovies, etc., and baked in a very hot oven" [OED], 1931, from Italian pizza, originally "cake, tart, pie," a name of uncertain origin. The 1907 "Vocabolario Etimologico della Lingua Italiana" reports it is said to be from dialectal pinza "clamp" (from Latin pinsere "to pound, stamp"). Klein suggests a connection with Medieval Greek pitta "cake, pie" (see pita). Watkins says it is (perhaps via Langobardic) from a Germanic source akin to Old High German bizzo, pizzo "bite, morsel," from Proto-Germanic *biton- (see bit (n.1)). Ayto ["Diner's Dictionary"] seems inclined toward this explanation, too.
The notion of taking a flat piece of bread dough and baking it with a savoury topping is a widespread one and of long standing — the Armenians claim to have invented it, and certainly it was known to the ancient Greeks and Romans — but it is Italy, and particularly Naples, that has given its version of the dish to the world. ... Since then it has undergone a series of metamorphoses in base, topping, and general character that would make it hard for Neapolitans to recognize as their own, but which have transformed it into a key item on the international fast-food menu. [Ayto]
A pizza is manufactured, as far as I can ascertain, by garnishing a slab of reinforced asphalt paving with mucilage, whale-blubber and the skeletons of small fishes, baking same to the consistency of a rubber heel, and serving piping-hot with a dressing of molten lava. ["Simon Stylites," in The Bergen Evening Record, May 15, 1931]