Etymology
Advertisement
acidic (adj.)

"containing a large amount of the acid element," 1877, originally in geology; see acid (n.) + -ic. The geological use was chemical, in reference to the acid element (silicon, etc.) in certain salts, and was opposed to basic.

Related entries & more 
Advertisement
acidulous (adj.)

"sub-acidic, slightly sour" (of cream of tartar, oranges, etc.), 1766, also used figuratively for "sour-tempered;" from Latin acidulus "slightly sour," a diminutive of acidus (see acid (adj.)).

Related entries & more 
acidophilus (adj.)

1920, used of milk fermented by acidophilic bacteria, from acidophil (1900), indicating "easily stained by acid dyes," a hybrid word, from Latin acidus "acidic, sour, tart" (see acid (adj.)) + Greek philos "loving" (see -phile); the bacteria so called because they stain easily with an acid dye.

Related entries & more