"apparatus," 1820, American English, from fixing "act of putting in order" (c. 1600), verbal noun from fix (v.). American English sense of "food, garnishing" is attested from 1839.
the recipe lists all the fixings for a salad
an elaborate formal dinner with all the fixings
fixate
fixation
fixative
fixed
fixer
fixings
fixity
fixture
fizgig
fizz
fizzle